AUTHOR INFORMATION

Section 1 of 12

Authored by A Antoine Kazzi, MD, Chief of Service, Department of Emergency Medicine, Medical Director of the Emergency Unit, American University of Beirut

Coauthored by Ziad N Kazzi, MD, Assistant Professor, Medical Toxicologist, Department of Emergency Medicine, University of Alabama in Birmingham

A Antoine Kazzi, MD, is a member of the following medical societies: American Academy of Emergency Medicine, American Medical Association, California Medical Association, and Society for Academic Emergency Medicine

Edited by Steven A Conrad, MD, PhD, Chief, Department of Emergency Medicine; Chief, Multidisciplinary Critical Care Service, Professor, Department of Emergency and Internal Medicine, Louisiana State University Health Sciences Center; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Eugene Hardin, MD, FACEP, FAAEM, Chair and Associate Professor, Department of Emergency Medicine, Charles R Drew University of Medicine and Science; Chair, Department of Emergency Medicine, Martin Luther King, Jr/Drew Medical Center; John Halamka, MD, Chief Information Officer, CareGroup Healthcare System, Assistant Professor of Medicine, Department of Emergency Medicine, Beth Israel Deaconess Medical Center; Assistant Professor of Medicine, Harvard Medical School; and Barry Brenner, MD, PhD, FACEP, Professor of Emergency Medicine, Professor of Internal Medicine, and Professor of Anatomy and Neurobiology, Research Director, Department of Emergency Medicine, University of Arkansas for Medical Sciences

Author's Email:	A Antoine Kazzi, MD
Editor's Email:	Steven A Conrad, MD, PhD

eMedicine Journal, June 13 2006, VOLUME 7, Number 6

INTRODUCTION

Section 2 of 12

Background: Diverticular disease is a common disorder, yet it was not recognized as a pathologic entity until the mid-19th century. Diverticulitis and lower gastrointestinal (GI) bleeding secondary to diverticulosis are the main complications of clinical importance to emergency physicians.

Pathophysiology: Diverticular disease may involve any part of the GI tract. Typically acquired, diverticular disease may be congenital, such as Meckel iliac diverticulum (although this is rare). Diverticula are herniations of the mucosa and submucosa or the entire wall thickness through the muscularis, as seen in congenital diverticula. The sigmoid is the most commonly affected segment (95-98%); however, diverticular disease also can involve the descending, ascending, and transverse colon as well as the jejunum, ileum, and duodenum.

Precise etiology of this disease is unknown. High intraluminal pressure and a weak colonic wall at the sites of nutrient vessel penetration into the muscularis may lead to herniation. The condition also may be caused by abnormal colonic motility, defective muscular structure, defects in collagen consistency (ie, increased cross-linking of collagen), and aging.

Diverticulitis is an abscess or peridiverticular inflammation initiated by the rupture of a microscopic mucosal abscess into the mesentery. The infection may progress, fistulize, obstruct, or spontaneously resolve.

Acute diverticulitis results from the inspissation of fecal material in the neck of the diverticulum and resultant bacterial replication. Lower GI bleeding from diverticulosis results from rupture of the small blood vessels that are stretched while coursing over the dome of the diverticula.

Frequency:

• In the US: Diverticular disease occurs frequently, especially among elderly patients. One third of the general population develops diverticulosis by age 45 years and two thirds by age 85 years.

Mortality/Morbidity: Mortality and morbidity are related to complications of diverticulosis, which are mainly diverticulitis and lower GI bleeding. These occur in 10-20% of patients with diverticulosis during their lifetime.

Race:

• Diverticular disease primarily is a disease of industrialized Western societies.

• Cultural diet may influence prevalence.

• In contrast to westerners, diverticular disease among Asians demonstrates right-sided predominance. A Japanese study conducted over 15 years has shown in their Asian population a steady increase in the incidence of right-sided diverticulitis but no increase in the incidence of its left-sided counterpart.

Sex: Male-to-female ratio is equal.

Age:

• Incidence rises with age.

• Diverticular disease is rare in people younger than 40 years.

• Morbidity has been traditionally reported to be worse in younger patients. However, a 1997 study by Spivak et al looking at the natural history of diverticulitis in patients younger than 45 years old found no worse course than in adults.

CLINICAL

Section 3 of 12

History:

• Clinical historical features of inflammatory disease include the following:

• Abdominal pain - Occurs mostly in the left lower quadrant and tends to be steady, severe, and deep

• History of fever suggestive of diverticulitis

• Previous episodes of dull, colicky, and diffuse abdominal pain accompanied with flatulence, distention, and change in bowel habits (diverticulosis)

• Altered bowel habits including diarrhea, increased constipation, and tenesmus (physician may note obstipation when treating a complicating bowel obstruction)

• Nausea and vomiting

• Dysuria, pyuria, and urinary frequency if bladder or ureter are irritated

• History of pneumaturia or recurrent urinary tract infections (colovesicular fistulas)

• Feculent vaginal discharge (fistulas with the uterus or vagina)

• Severe and generalized abdominal pain (diffuse peritonitis)

• Back or lower extremity pain (perforation)

• Establish history of hemorrhagic disease, including the following:

• Lower GI bleeding from diverticulosis occurs in the form of bright red-colored or wine-colored stools.

• Onset of bleeding typically is sudden, painless, and accompanied by an urge to defecate.

• Amount of bleeding typically is massive and tends to stop spontaneously.

• Ascertain a previous history of gastric or duodenal ulcers, liver disease, or GI bleeding.

• Discomfort and pain upon defecation indicate hemorrhoids or anal fissures.

• History of weight loss and mucus in the stools indicates inflammatory bowel disease.

• Establish list of medications used (nonsteroidal anti-inflammatory drugs [NSAIDs], steroids) and of alcohol abuse.

• Establish bleeding tendencies.

Physical:

• Establish localized tenderness, rebound tenderness, and/or guarding. This is essential in the clinical management of diverticular disease. Their presence indicates diverticulitis.

• When associated with GI bleeding, tenderness is not typical of diverticular etiology; it indicates other disease processes.

• Assess vital signs to determine hemodynamic stability and profile of presentation.

• Low-grade fever commonly is found in diverticulitis.

• Rectal examination identifies tenderness, establishes the color of stools, and determines the presence and extent of GI bleeding. A mass may be seen in the cul-de-sac.

• Diffuse abdominal tenderness, rebound, absent bowel sounds, and/or high-grade fever may be elicited. These indicate possible complications of perforation and/or peritonitis.

• Pelvic and rectal examinations establish the correct diagnosis.

• Palpate for any mass or fullness, particularly in the left iliac fossa.

• Abdomen may be distended and tympanic.

• Pain may be acute and located mainly in the left lower quadrant.

Causes:

• Low-fiber diet is the highest risk factor. Common in industrialized nations, a low-fiber diet forms low-bulk stool that lead to increased segmentation of the colon during propulsion, causing increased intraluminal pressure and formation of diverticula.

• High fat and beef diets also cause diverticular disease, probably for the same reasons as above.

• Genetic causes exist. Asians have right-sided diverticula preponderance. In westerners, diverticula develop mostly on the left side.

• Aging leads to change in collagen structure, such as increased cross-linking and acid solubility.

• Colonic motility disorders are a cause.

• Corticosteroids but not nonsteroidal anti-inflammatory therapy have recently been shown to increase the risk of diverticulitis.

• Colonic segmentation: Nonpropulsive contractions produce isolated segments or little chambers with high pressure within.

• Defects in colonic wall strength can cause the condition.

DIFFERENTIALS

Section 4 of 12

Abdominal Trauma, Blunt
Lymphogranuloma Venereum
Syphilis
Tuberculosis

Other Problems to be Considered:

Actinomycosis
Amebiasis
Angiodysplasias
Carcinoma of the colon (particularly distal colon)
Collagen diseases
Fecal impaction
Foreign body granuloma
Gonococcal and nongonococcal proctitis
Infectious colitis
Irritable bowel syndrome
Ischemic colitis
Meckel diverticulitis
Postirradiation proctosigmoiditis

WORKUP

Section 5 of 12

Lab Studies:

• Complete blood count: CBC identifies leukocytosis and/or a left shift in acute diverticulitis; however, 60% of patients may have a normal white blood cell count, particularly elderly and immunocompromised patients. Manage GI bleeding by establishing hematocrit.

• Type and cross-match blood; also obtain coagulation and bleeding time profiles in patients with lower GI bleeding or frank peritonitis.

• Urinalysis/urine culture: This identifies urinary tract infections and hematuria. It indicates existence of colovesicular fistulas or if diverticular disease is the etiology.

• Serum electrolytes: In the absence of a prerenal picture, an elevated BUN/creatinine ratio indicates the presence of blood in the GI tract.

• Lipase/amylase and liver function tests: These may help establish other etiologies or features in the presentation of abdominal pain. This is particularly important when patients present atypically (eg, steroid therapy, elderly patients, those with diabetes) or relatively late in the course of an inflammatory process with generalized tenderness or frank peritonitis.

• Perform blood cultures if acute diverticulitis is suspected prior to infusion of empiric antibiotic therapy.

Imaging Studies:

• Plain radiographs: An acute abdominal series, with flat and upright abdominal imaging, identifies signs of intestinal irritation (ileus) and two thirds of visceral perforations (free air). Radiographs can identify volvulus, bowel obstruction, renal stones, and occasionally suggest the existence of intraabdominal masses.

• CT scan: This is the test of choice for acute diverticulitis. Look for diverticula, localized colonic wall thickening (>5 mm), abscesses, fistulas, and pericolic fat inflammation and exclude other pathologies, such as a tubo-ovarian abscess or aortic or other vascular blood leakage. Administering rectal contrast with no intravenous contrast has been shown in one study to be equally as sensitive as CT scans where oral contrast was administered.

• Double-contrast enema: This is useful in the diagnosis of diverticulosis yet contraindicated in acute diverticulitis because of the fear of perforation, leak of barium and intestinal content, and subsequent severe peritonitis.

• Water-soluble contrast enema: Water-soluble contrast is safe in intraluminal imaging and useful in the workup of patients with suspected diverticular disease. However, a prospective study in 2000 has shown CT scanning to have a 97% sensitivity rate as compared to 92% sensitivity rate for water-soluble contrast enema. CT scanning was also superior in detecting abscesses.

• Ultrasonography: Ultrasonography is a noninvasive test used by a number of investigators and has been reported in one study to be equally sensitive and specific to CT scanning in aiding in diagnosis of acute colonic diverticulitis. Transrectal ultrasonography with transabdominal ultrasonography may have additional benefits. Unfortunately, sonography is not often readily available and its reliability is more operator dependent.

• Tc-blood cell scan: In patients with lower GI bleeding, perform a Tc-blood cell scan after stabilizing the patient to identify the rate of bleeding (down to 0.12 mL/min). Follow with a selective mesenteric arteriogram to identify the source.

• Colonoscopy: If these steps fail to identify the etiology and site of bleeding, perform a total colonoscopy.

• Magnetic resonance imaging (MRI): MRI was evaluated in one study and found that it accurately identified diverticulitis in 10 out of 11 patients. Larger studies are needed to further evaluate the modality of MRI in aiding in diagnosis of diverticulitis.

Procedures:

• Endoscopy: Endoscopy is useful in diagnosing diverticular disease and in establishing the source of lower GI bleeding. Endoscopy is avoided in acute diverticulitis because of the fear of perforation and peritonitis. A nasogastric tube is usually inserted first to exclude most upper GI causes of rectal bleeding. A 2000 study found that aggressive urgent colonoscopy performed by a dedicated endoscopy team with experience in interventional procedures uses colonoscopy as both a diagnostic measure and a therapeutic measure.

TREATMENT

Section 6 of 12

Prehospital Care:

• Start intravenous fluids and oxygen, particularly during lengthy prehospital periods.

• Scenarios that usually require mobilization of prehospital resources are severe abdominal pain, GI bleeding, or hemodynamic instability with a diagnosis that has not yet been established.

Emergency Department Care:

• When a patient presents with classic signs and symptoms of uncomplicated diverticulosis, discharge on antispasmodics and a high-fiber diet with a follow-up sigmoidoscopy at a later time. Typically, no fever, leukocytosis, palpable mass, or other evidence of acute diverticulitis is present.

• For patients who present with signs and symptoms of acute diverticulitis, take the following actions:
  • Administer intravenous fluid resuscitation as indicated.

  • Give the patient nothing by mouth (NPO).

  • In a recent retrospective study, patients who underwent surgical therapy after an initial episode of acute diverticulitis had less recurrence than those who were managed medically.

  • Defer use of analgesics, since they may increase colonic spasm (eg, morphine) or mask peritoneal signs of perforation and peritonitis. Emergency physicians question whether short-acting narcotics mask peritoneal signs when performing adequate serial abdominal examinations.

  • Insert a nasogastric tube if patient is vomiting or colonic obstruction is suspected.

  • Administer empiric broad-spectrum intravenous (IV) antibiotics. Antibiotics should target anaerobes such as Bacteroides fragilis and Peptostreptococcus, Peptococcus, and Clostridium species, as well as aerobes such as Escherichia coli and Klebsiella, Proteus, Streptococcus, and Enterobacter species. If an abscess is suspected, coverage also should include Pseudomonas aeruginosa.

• Most patients diagnosed with acute diverticulitis should be hospitalized; most improve in 48-72 hours.

• Patients with mild-to-moderate acute diverticulitis and no systemic signs or localized peritonitis may be discharged home on a low-residue food diet and oral antibiotics covering gram-negative organisms and anaerobes. Instruct patients to return if the pain increases or signs of systemic infection develop, assuming the patient is a normal host with no clinical evidence of other morbid conditions requiring admission or additional workup.

• Perform the following if patient presents with signs and symptoms of acute GI bleeding:
  • Address standard ABCs appropriately.

  • Administer supplemental oxygen.

  • Maintain hemodynamic stability.

  • Secure 2 large-bore IV lines.

  • Administer lactated Ringer solution. Once 2 liters of Ringer are administered, transfuse blood.

  • Insert a nasogastric tube to exclude potential upper GI source for the bleeding.

  • Search for comorbid conditions, such as an acute myocardial infarction from the hypovolemic state.

  • Insert a urinary catheter to monitor output, which reflects adequacy of resuscitation.

  • Secure the appropriate emergent consultations quickly.

  • Admit patient to an intensive care setting.

• Subsequent management centers on identifying the source of bleeding.

Consultations: Consult with general surgery if the patient presents with any of the following:

• Sepsis, fistula, or obstruction

• Clinical evidence of perforation of viscus

• Failure of medical therapy or clinical deterioration

• Inability to exclude carcinoma or recurrence of the disease

• Young age, use of steroids, immunocompromised patients, and right-sided diverticulitis (relative indications for surgical intervention)

MEDICATION

Section 7 of 12

Goals of pharmacotherapy are to treat the infection and prevent complications.

Drug Category: Antibiotics -- Therapy for diverticulitis must cover all likely pathogens in the clinical setting including anaerobes (eg, bacterids) and gram-negative organisms (eg, Enterobacteriaceae, enterococci). Complicated diverticulitis is commonly treated using a combination of metronidazole or clindamycin with an aminoglycoside or third-generation cephalosporin. More recent regimens commonly used include beta-lactam/beta-lactamase combinations (eg, ampicillin/sulbactam, piperacillin/tazobactam). In more severe cases, imipenem may be used. Milder cases of diverticulitis are treated on an outpatient basis with a PO regimen that includes ciprofloxacin with metronidazole. Recently, rifampin has been used in the treatment of milder cases of acute diverticulitis. Initial studies evaluating the use of mesalazine have shown benefit when used in combination with another antibiotic, such as rifampin, in improving outcome and decreasing the frequency of recurrences.

Drug Name	Metronidazole (Flagyl) -- Active against various anaerobic bacteria and protozoa. Appears to be absorbed into the cells, and intermediate-metabolized compounds that are formed bind DNA and inhibit protein synthesis, causing cell death.
Adult Dose	Load 15 mg/kg IV over 1 h; followed by 7.5 mg/kg PO/IV q6h; not to exceed 4 g/d
Pediatric Dose	<12 years: Not established >12 years: Administer as in adults
Contraindications	Documented hypersensitivity; active organic disease of CNS such as epilepsy; blood dyscrasias or history of cardiac function impairment (because of sodium content); severe hepatic function impairment; lactation or first trimester of pregnancy
Interactions	May increase toxicity of anticoagulants, lithium, and phenytoin; cimetidine may increase toxicity of metronidazole; disulfiram reaction may occur with orally ingested ethanol
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in hepatic disease; monitor for seizures and development of peripheral neuropathy

Drug Name	Clindamycin (Cleocin) -- Lincosamide useful as treatment against serious skin and soft tissue infections caused by most staphylococci strains. Also effective against aerobic and anaerobic streptococci, except enterococci. Inhibits bacterial protein synthesis by inhibiting peptide chain initiation at the bacterial ribosome where it preferentially binds to the 50S ribosomal subunit, causing bacterial replication inhibition.
Adult Dose	150-450 PO mg q6h; 300-900 mg IV/IM q6-12h; not to exceed 4800 mg/d
Pediatric Dose	8-20 mg/kg/d PO as hydrochloride and 8-25 mg/kg/d as palmitate divided tid/qid; 20-40 mg/kg/d IV/IM divided tid/qid
Contraindications	Documented hypersensitivity; regional enteritis, ulcerative colitis, hepatic impairment, antibiotic-associated colitis
Interactions	Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects of clindamycin; antidiarrheals may delay absorption of clindamycin
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; associated with severe and possibly fatal colitis

Drug Name	Ampicillin (Omnipen, Marcillin) -- Interferes with bacterial cell wall synthesis during active replication, causing bactericidal activity against susceptible organisms.
Adult Dose	1-2 g PO qd divided q6h; 2-8 g IV/IM qd divided q4-6h
Pediatric Dose	50 mg/kg IV/IM
Contraindications	Documented hypersensitivity; life-threatening reactions to other beta-lactams
Interactions	Probenecid and disulfiram elevate ampicillin levels; allopurinol decreases ampicillin effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction

Drug Name	Amoxicillin (Amoxil, Polymox, Trimox) -- Used orally when outpatient management is indicated. Improves compliance because of dosing frequency and duration. Interferes with synthesis of cell wall mucopeptide during active replication, resulting in bactericidal activity against susceptible bacteria.
Adult Dose	500 mg PO tid for 6 d
Pediatric Dose	20-50 mg/kg/d PO divided q8h
Contraindications	Documented hypersensitivity
Interactions	Reduces efficacy of oral contraceptives; aspirin and probenecid increase amoxicillin concentrations; increased risk of bleeding with concomitant oral anticoagulants
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in renal impairment

Drug Name	Ciprofloxacin (Cipro) -- Bactericidal antibiotic that inhibits bacterial DNA synthesis and consequently replication by inhibiting DNA-gyrase in susceptible organisms. Indicated for pseudomonal infections and those from multidrug-resistant gram-negative organisms.
Adult Dose	250-500 mg PO q12h for 5-7 d; 200 mg IV q12h
Pediatric Dose	<18 years: Not recommended >18 years: Administer as in adults
Contraindications	Documented hypersensitivity; do not administer to pediatric patients, since quinolones may cause arthropathy in children because of cartilage hardening
Interactions	Antacids, iron salts, and zinc salts may reduce serum levels; administer antacids 2-4 h before or after taking fluoroquinolones; cimetidine may interfere with metabolism of fluoroquinolones; ciprofloxacin reduces therapeutic effects of phenytoin; probenecid may increase ciprofloxacin serum concentrations May increase toxicity of theophylline, caffeine, cyclosporine, and digoxin (monitor digoxin levels); may increase effects of anticoagulants (monitor PT)
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	In prolonged therapy, perform periodic evaluations of organ system functions (eg, renal, hepatic, hematopoietic); adjust dose in renal function impairment; superinfections may occur with prolonged or repeated antibiotic therapy

Drug Name	Cephalexin (Keflex, Biocef) -- Used orally when outpatient management is indicated. First-generation cephalosporin that inhibits bacterial replication by inhibiting bacterial cell wall synthesis. Bactericidal and effective against rapidly growing organisms forming cell walls. Primarily active against skin flora; typically used for skin structure coverage and as prophylaxis in minor procedures.
Adult Dose	250-500 mg PO q6h
Pediatric Dose	25-50 mg/kg/d PO divided q6h
Contraindications	Documented hypersensitivity
Interactions	Toxicity increases with aminoglycosides, furosemide, colistin, ethacrynic acid, and vancomycin
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in renal impairment

Drug Name	Imipenem and cilastatin (Primaxin) -- Used for treatment of multiple-organism infections in which other agents do not have wide-spectrum coverage or are contraindicated because of potential toxicity.
Adult Dose	250-500 mg IV q6h; in severe infections, may increase to 1g q6h; IM q12h; not to exceed total daily dose of 1500 mg
Pediatric Dose	10-15 mg/kg IV q6h
Contraindications	Documented hypersensitivity
Interactions	Coadministration with cyclosporine may increase CNS adverse effects of both agents; coadministration with ganciclovir may result in generalized seizures
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Adjust dose in renal insufficiency; avoid use in children <12 y

Drug Name	Cefoxitin (Mefoxin) -- Second-generation cephalosporin indicated for management of infections caused by susceptible gram-positive cocci and gram-negative rods. Many infections are caused by gram-negative bacteria, are resistant to some cephalosporins and penicillins, and respond to cefoxitin.
Adult Dose	1-2 g IV/IM q6-8h or q4h if infection is severe
Pediatric Dose	80-160 mg/kg/d IV divided q4-6h; higher doses for severe or serious infections; not to exceed 12 g/d
Contraindications	Documented hypersensitivity
Interactions	Probenecid may increase effects of cefoxitin; coadministration with aminoglycosides or furosemide may increase nephrotoxicity (closely monitor renal function)
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Bacterial or fungal overgrowth of nonsusceptible organisms may occur with prolonged use or repeated treatment; caution in patients with previously diagnosed colitis

Drug Name	Ticarcillin and clavulanate potassium (Timentin) -- Inhibits biosynthesis of cell wall mucopeptide and is effective during active replication. Antipseudomonal penicillin and beta-lactamase inhibitor that provides coverage against most gram-positive and gram-negative bacteria and most anaerobes.
Adult Dose	INF 1 vial containing ticarcillin 3 g IV and clavulanate 0.1 g IV q4-6h over 30 min
Pediatric Dose	75 mg/kg IV q6h
Contraindications	Documented hypersensitivity; do not treat severe pneumonia, bacteremia, pericarditis, emphysema, meningitis, and purulent or septic arthritis with oral penicillin during acute stage
Interactions	Tetracyclines may decrease effects of ticarcillin; high concentrations of ticarcillin may physically inactivate aminoglycosides if administered in same IV line; effects when administered concurrently with aminoglycosides are synergistic; probenecid may increase penicillin levels
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Perform CBC counts prior to initiation of therapy and at least weekly during therapy; monitor for liver function abnormalities by measuring AST and ALT during therapy; exercise caution in patients diagnosed with hepatic insufficiencies; perform urinalysis and BUN and creatinine determinations during therapy and adjust dose if values become elevated; monitor blood levels to avoid possible neurotoxic reactions

Drug Name	Ampicillin-sulbactam sodium (Unasyn) -- Combination antimicrobial agent that uses beta-lactamase inhibitor with ampicillin. Covers skin, enteric flora, and anaerobes.
Adult Dose	1 g ampicillin/0.5 g sulbactam IV or 2 g ampicillin/1 g sulbactam q6h; not to exceed 4 g of sulbactam/d
Pediatric Dose	<12 years: 100-200 mg ampicillin/kg/d (150-300 mg Unasyn) IV divided q6h >12 years: Administer as in adults; not to exceed 4 g/d sulbactam or 8 g/d ampicillin
Contraindications	Documented hypersensitivity
Interactions	Probenecid and disulfiram elevate ampicillin levels; allopurinol decreases ampicillin effects and has additive effects on ampicillin rash; may decrease effects of oral contraceptives
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Adjust dose in renal failure; evaluate rash and differentiate from hypersensitivity reaction

Drug Name	Rifampin (Rimactane, Rifadin IV, Rifadin) -- Inhibits RNA synthesis in bacteria by binding to beta subunit of DNA-dependent RNA polymerase, which, in turn, blocks RNA transcription.
Adult Dose	10 mg/kg/d PO/IV; not to exceed 600 mg/d
Pediatric Dose	10-20 mg/kg PO/IV; not to exceed 600 mg/d
Contraindications	Documented hypersensitivity
Interactions	Induces microsomal enzymes, which may decrease effects of acetaminophen, oral anticoagulants, barbiturates, benzodiazepines, beta-blockers, chloramphenicol, oral contraceptives, corticosteroids, mexiletine, cyclosporine, digitoxin, disopyramide, estrogens, hydantoins, methadone, clofibrate, quinidine, dapsone, tazobactam, sulfonylureas, theophyllines, tocainide, and digoxin; blood pressure may increase with coadministration of enalapril; coadministration with isoniazid or pyrazinamide may result in higher rate of hepatotoxicity than with either agent alone (discontinue 1 or both agents if alterations in LFTs occur)
Pregnancy	C - Safety for use during pregnancy has not been established.
Precautions	Obtain CBCs and baseline clinical chemistries prior to and throughout therapy; in liver disease, weigh benefits against risk of further liver damage; interruption of therapy and high-dose intermittent therapy are associated with thrombocytopenia that is reversible if therapy is discontinued as soon as purpura occurs; if treatment is continued or resumed after appearance of purpura, cerebral hemorrhage or death may occur

Drug Name	Piperacillin and tazobactam sodium (Zosyn) -- Antipseudomonal penicillin plus beta-lactamase inhibitor. Inhibits biosynthesis of cell wall mucopeptide and is effective during stage of active multiplication.
Adult Dose	3/0.375 g (piperacillin 3 g and tazobactam 0.375 g) IV q6h
Pediatric Dose	<12 years: Not established >12 years: Administer as in adults
Contraindications	Documented hypersensitivity; severe pneumonia, bacteremia, pericarditis, emphysema, meningitis, and purulent or septic arthritis should not be treated with an oral penicillin during the acute stage
Interactions	Tetracyclines may decrease effects of piperacillin; high concentrations of piperacillin may physically inactivate aminoglycosides if administered in same IV line; when administered concurrently with aminoglycosides, effects are synergistic; probenecid may increase penicillin levels; high-dose parenteral penicillins may result in increased risk of bleeding
Pregnancy	B - Usually safe but benefits must outweigh the risks.
Precautions	Perform CBCs prior to initiation of therapy and at least weekly during therapy; monitor for liver function abnormalities by measuring AST and ALT levels during therapy; caution in patients with hepatic insufficiencies; perform urinalysis, and BUN and creatinine determinations during therapy and adjust dose if values become elevated; monitor blood levels to avoid possible neurotoxic reactions

FOLLOW-UP

Section 8 of 12

Further Inpatient Care:

• Modalities used to stop bleeding include the following:

• Intra-arterial vasopressin

• Embolization was successful in 85% of cases based on a recent meta-analysis.

• Endoscopic homeostasis by epinephrine injection, heater probe, or bipolar coagulation

• If bleeding persists or clinical condition does not permit the above modalities, perform emergency surgery.

Further Outpatient Care:

• If the patient is not admitted and the episode resolves, arrange for barium contrast enema.

• Recommend a fiber-rich diet.

Transfer:

• Transfer patient if medical center has no general surgeons or radiologic facilities.

• Do not transfer patients with active GI bleeding and impending or actual peritonitis.

Deterrence/Prevention:

• High-fiber diet

• Psyllium

• Agar

• Methylcellulose

Complications:

• Fistulas
  • Fistulas occur secondary to chronic diverticulitis or recurrent episodes of acute diverticulitis. Chronic inflammatory process causes adhesions to form between the colon and neighboring organs.

  • Colovesicular fistulas are the most common (most occur in men), followed by colovaginal fistulas (80% occur in women who have undergone hysterectomies). Additionally, fistulas to the integument, uterus, fallopian tubes, and pelvic floor have been reported.

  • Contrast enemas, retrograde dye studies, or CT scan confirms the diagnosis.

  • Treatment consists of surgical resection of the involved colon.

• Hemorrhage

• Perforation with peritonitis
  • Clinical presentation typically is more severe than in acute diverticulitis.

  • It often is diagnosed by seeing free air on plain x-rays. Barium enemas and endoscopy are contraindicated.

  • Treat surgically. Laparoscopic resection has comparable results to open resections when performed in experienced institutions.

• Abscess
  • Suspect abscess when the patient fails to respond to medical therapy. It may be palpable.

  • CT scan or ultrasonography typically permits its diagnosis.

  • Treat with percutaneous drainage. Some report successful transrectal and transvaginal drainage in selected situations.

• Colonic obstruction
  • Colonic obstruction results from repetitive episodes of diverticulitis that cause mycosis coli or colonic muscular wall thickening.

  • Differentiate from other causes of obstruction, such as ischemia, colitis, or carcinoma, by contrast enemas or endoscopy.

  • If diagnosis is uncertain or obstructive symptoms develop, perform resection.

Prognosis:

• The Hinchey staging system reflects surgical outcome. It guides surgeons in selecting their operative strategy and reflects the risk of secondary complications after the acute episode is managed successfully.

• Stage I - Pericolic abscess

• Stage II - Pelvic abscess

• Stage III - Purulent peritonitis

• Stage IV - Feculent peritonitis

• Stage I disease treated by primary resection has 0% mortality, while stages II and III have 5% and 18% mortality, respectively.

• Prognosis is good with early detection and treatment of complications.

• Of those with a first episode of diverticulitis who successfully are treated medically, 67% do not have subsequent attacks requiring hospitalization, and 33% have recurrences; 2-3 recurrences in 1-2 years is an indication to electively remove the involved segment of colon.

• Of those with diverticular bleeding, as many as 20% rebleed within months to years.

Patient Education:

• Educate the patient on the importance of dietary fiber.

• For excellent patient education resources, visit eMedicine's Esophagus, Stomach, and Intestine Center. Also, see eMedicine's patient education article, Diverticulosis and Diverticulitis.

MISCELLANEOUS

Section 9 of 12

Medical/Legal Pitfalls:

• Failure to promptly initiate empiric antibiotic therapy with clinically evident diverticulitis

• Failure to promptly diagnose visceral perforation or peritonitis

• Failure to adequately treat patients younger than 40 years

• Failure to appreciate that right lower quadrant pain in an elderly patient or a premenopausal woman may be caused by acute diverticulitis

Special Concerns:

• Hemorrhage secondary to diverticulosis in elderly persons carries a worse morbidity and mortality.

TEST QUESTIONS

Section 10 of 12

CME Question 1: Which of the following measures should not be taken in a patient with suspected acute diverticulitis?

A: Placement of a nasogastric tube
B: Barium contrast enema
C: CT scan of the abdomen and pelvis
D: Giving the patient nothing by mouth
E: Starting empirical antibiotic treatment

The correct answer is B: A barium contrast enema is contraindicated in acute diverticulitis. The concern is a potential barium leak into the peritoneum in the instance of a perforation. The use of water-soluble contrasts is safe. All of the other procedures are indicated.

CME Question 2: Which of the following is not a symptom of acute diverticulitis?

A: Lower abdominal pain
B: Change in bowel habits
C: Nausea or vomiting
D: Painless lower gastrointestinal bleeding
E: Fever

The correct answer is D: Rectal bleeding is rare in acute diverticulitis. Diverticulitis is never painless. Conversely, lower gastrointestinal bleeding secondary to diverticulosis is typically painless. All other symptoms are common features in acute diverticulitis.

Pearl Question 1 (T/F): Those older than 45 years are most affected by diverticular disease.

The correct answer is True: Persons older than 45 years mostly are affected by diverticular disease. One third of the population older than 45 years and two thirds of those older than 85 years have diverticular disease. It can affect younger age groups; when it does, it may have a more complicated course.

Pearl Question 2 (T/F): Colovesicular diverticula are the most common type of fistulas that form secondary to recurrent episodes of diverticulitis.

The correct answer is True: Colovesicular diverticula are the most common, followed by colovaginal fistulas. Any adjacent structure can be involved.

Pearl Question 3 (T/F): Leukocytosis is a reliable indicator of acute diverticulitis.

The correct answer is False: Leukocytosis is initially absent at presentation in the majority of patients with proven acute diverticulitis. This is particularly true in elderly and immunocompromised patients.

Pearl Question 4 (T/F): The sigmoid colon is the bowel segment most commonly affected by diverticular disease.

The correct answer is True: The sigmoid colon is affected most commonly, although any bowel segment can be involved.

PICTURES

Section 11 of 12

Caption: Picture 1. Diverticulitis acute fatty stranding.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT
Caption: Picture 2. "Thumbprinting" (seen in left mid quadrant) on a plain abdominal radiograph.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: X-RAY
Caption: Picture 3. "Thumbprinting" (seen in left mid quadrant) on a plain abdominal radiograph (close-up image).
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: X-RAY
Caption: Picture 4. Thickening of the bowel wall in the descending colon due to bowel edema can be seen in the left lower quadrant on this plain abdominal radiograph. Note the narrowed colonic lumen. Note the CT scan images in this article are from the same 62-year-old patient with diverticulitis.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: X-RAY
Caption: Picture 5. Thickening of the bowel wall in the descending colon due to bowel edema can be seen in the left lower quadrant on this plain abdominal radiograph. Note the narrowed colonic lumen. Note the CT scan images in this article are from the same 62-year-old patient with diverticulitis.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: X-RAY
Caption: Picture 6. Thickening of the bowel wall in the descending colon due to bowel edema can be seen in the left lower quadrant on this CT scan. Note the narrowed colonic lumen (contrast in the lumen is white). Note the hypodense (dark) spot in the bottom right of the edematous colonic wall; this spot is an abscess that is forming within the bowel wall in a 62-year-old patient with diverticulitis.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT
Caption: Picture 7. Sigmoid diverticulitis in a 50-year-old male patient with history of diverticulosis and left lower abdominal pain and tenderness.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT
Caption: Picture 8. Thickening of the bowel wall in the descending colon due to bowel edema can be seen in the left lower quadrant on this CT scan. Note the narrowed colonic lumen (contrast in the lumen is white). Note the hypodense (dark) spot in the bottom right of the edematous colonic wall; this spot is an abscess that is forming within the bowel wall in a 62-year-old patient with diverticulitis.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT
Caption: Picture 9. Sigmoid diverticulitis in a 50-year-old male patient with history of diverticulosis and left lower abdominal pain and tenderness. Images 9-12 are sections from the same patient.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT
Caption: Picture 10. Sigmoid diverticulitis in a 50-year-old male patient with history of diverticulosis and left lower abdominal pain and tenderness. Images 9 and 11-12 are sections from the same patient.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT
Caption: Picture 11. Phlegmon. Sigmoid diverticulitis in a 50-year-old male patient with history of diverticulosis and left lower abdominal pain and tenderness. Images 11-12 are consecutive sections of the patient in Image 9-10 showing a phlegmon.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT
Caption: Picture 12. Phlegmon. Sigmoid diverticulitis in a 50-year-old male patient with history of diverticulosis and left lower abdominal pain and tenderness. Images 9-11 are sections from the same patient.
	View Full Size Image
	eMedicine Zoom View (Interactive!)
Picture Type: CT

BIBLIOGRAPHY

Section 12 of 12

• Ambrosetti P, Grossholz M, Becker C, et al: Computed tomography in acute left colonic diverticulitis. Br J Surg 1997 Apr; 84(4): 532-4[Medline].
• Baron TH, Morgan DE: Endoscopic transrectal drainage of a diverticular abscess. Gastrointest Endosc 1997 Jan; 45(1): 84-7[Medline].
• Bennett WG, Cerda JJ: Benefits of dietary fiber. Myth or medicine? Postgrad Med 1996 Feb; 99(2): 153-6, 166-8, 171-2 passim[Medline].
• Bono MJ: Lower gastrointestinal tract bleeding. Emerg Med Clin North Am 1996 Aug; 14(3): 547-56[Medline].
• Foutch PG: Diverticular bleeding: are nonsteroidal anti-inflammatory drugs risk factors for hemorrhage and can colonoscopy predict outcome for patients?. Am J Gastroenterol 1995 Oct; 90(10): 1779-84[Medline].
• Freeman SR, McNally PR: Diverticulitis. Med Clin North Am 1993 Sep; 77(5): 1149-67[Medline].
• Greenberg AS, Gal R, Coben RM: A retrospective analysis of medical or surgical therapy in young patients with diverticulitis. Aliment Pharmacol Ther 2005 May 15; 21(10): 1225-9[Medline].
• Heverhagen JT, Ishaque N, Zielke A, et al: Feasibility of MRI in the diagnosis of acute diverticulitis: initial results. MAGMA 2001 Mar; 12(1): 4-9[Medline].
• Jensen DM, Machicado GA, Jutabha R, Kovacs TO: Urgent colonoscopy for the diagnosis and treatment of severe diverticular hemorrhage. N Engl J Med 2000 Jan 13; 342(2): 78-82[Medline].
• Jones DJ: ABC of colorectal diseases. Diverticular disease. BMJ 1992 May 30; 304(6839): 1435-7[Medline].
• Khanna A, Ognibene SJ, Koniaris LG: Embolization as first-line therapy for diverticulosis-related massive lower gastrointestinal bleeding: evidence from a meta-analysis. J Gastrointest Surg 2005 Mar; 9(3): 343-52[Medline].
• Lee EC, Murray JJ, Coller JA, et al: Intraoperative colonic lavage in nonelective surgery for diverticular disease. Dis Colon Rectum 1997 Jun; 40(6): 669-74[Medline].
• McCarthy DW, Bumpers HL, Hoover EL: Etiology of diverticular disease with classic illustrations. J Natl Med Assoc 1996 Jun; 88(6): 389-90[Medline].
• Mizuki A, Nagata H, Tatemichi M: The out-patient management of patients with acute mild-to-moderate colonic diverticulitis. Aliment Pharmacol Ther 2005 Apr 1; 21(7): 889-97[Medline].
• Mpofu S, Mpofu CM, Hutchinson D, et al: Steroids, non-steroidal anti-inflammatory drugs, and sigmoid diverticular abscess perforation in rheumatic conditions. Ann Rheum Dis 2004 May; 63(5): 588-90[Medline].
• Pradel JA, Adell JF, Taourel P: Acute colonic diverticulitis: prospective comparative evaluation with US and CT. Radiology 1997 Nov; 205(2): 503-12[Medline].
• Ramirez FC, Johnson DA, Zierer ST, et al: Successful endoscopic hemostasis of bleeding colonic diverticula with epinephrine injection. Gastrointest Endosc 1996 Feb; 43(2 Pt 1): 167-70[Medline].
• Schoetz DJ: Uncomplicated diverticulitis. Indications for surgery and surgical management. Surg Clin North Am 1993 Oct; 73(5): 965-74[Medline].
• Sher ME, Agachan F, Bortul M, et al: Laparoscopic surgery for diverticulitis. Surg Endosc 1997 Mar; 11(3): 264-7[Medline].
• Tancer ML, Veridiano NP: Genital fistulas caused by diverticular disease of the sigmoid colon. Am J Obstet Gynecol 1996 May; 174(5): 1547-50[Medline].
• Trepsi E, Colla C, Panizza P, et al: [Therapeutic and prophylactic role of mesalazine (5-ASA) in symptomatic diverticular disease of the large intestine. 4 year follow-up results]. Minerva Gastroenterol Dietol 1999 Dec; 45(4): 245-52[Medline].
• Tursi A: Acute diverticulitis of the colon--current medical therapeutic management. Expert Opin Pharmacother 2004 Jan; 5(1): 55-9[Medline].
• Wedell J, Banzhaf G, Chaoui R, et al: Surgical management of complicated colonic diverticulitis. Br J Surg 1997 Mar; 84(3): 380-3[Medline].
• Wess L, Eastwood MA, Wess TJ, et al: Cross linking of collagen is increased in colonic diverticulosis. Gut 1995 Jul; 37(1): 91-4[Medline].

eMedicine Journals > Emergency Medicine > Gastrointestinal > Diverticular Disease

Please email us with any comments you have on our new chapter format.

Author Information | Introduction | Clinical | Differentials | Workup | Treatment | Medication | Follow-up | Miscellaneous | Test Questions | Pictures | Bibliography