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Diverticular Disease
Jin Sol Oh, MD
David Hardy, MD, RPVI
Steven B. Holsten Jr., MD, FACS
image BASICS
Diverticular disease includes asymptomatic diverticulosis, symptomatic uncomplicated diverticular disease, uncomplicated diverticulitis, complicated diverticulitis, and diverticular bleeding.
  • Diverticulum (single) or diverticula (multiple) are outpouchings of colonic mucosa and submucosa through weakened muscle layers in the colonic wall.
    • Less common in vegetarians and more common in cultures with low-fiber diets
    • Most diverticula occur on the left side of the colon; Asian populations have more right-sided diverticula.
    • Prevalence of diverticulosis and the number of diverticula increase with age.
  • Symptomatic uncomplicated diverticular disease: recurrent abdominal pain attributed to diverticula in the absence of macroscopically overt colitis or diverticulitis (1)
  • Uncomplicated diverticulitis: diverticular inflammation and/or infection without systemic sequelae
  • Complicated diverticulitis inflammation/infection with secondary abscess formation, bowel obstruction or perforation, peritonitis, fistula, or stricture formation
  • Diverticular bleeding occurs in 3-5% of patients with diverticular disease.
    • Accounts for >40% of lower GI bleeds and 30% of cases of hematochezia in general
    • Bleeding more common with right-sided diverticula
  • System(s) affected: entire GI tract except the rectum
  • Diverticulosis affects 60% of the population above the age of 60, and 70% by age of 80.
  • 1-2% of the general population is affected by diverticulitis over the course of a lifetime (1).
  • Traditionally, 15-25% of patients with diverticulosis were thought to develop diverticulitis in their lifetime. The true incidence of diverticulitis is likely <5%.
  • Yearly mortality rate: 2.5/100,000
  • Increased from 62 to 75/100,000 persons from 1998 to 2005; large increase in incidence for patients <45 years of age due to changes in diet
  • Male = female overall. More common in men <65 years of age and more common in women >65 years
Diverticula form where intestinal blood flow (vasa recta) penetrates the colonic mucosa. This results in decreased resistance to intraluminal pressure. Diverticulitis occurs when there is diverticular inflammation, infection, and/or perforation.
  • Age-related degeneration of mucosal wall, increased intraluminal pressure from dense, fiber-depleted stools, and abnormal colonic motility contribute to diverticular disease.
  • Thinning of the vasa recta over the neck of the diverticula increases susceptibility to bleeding.
  • Diverticulitis occurs when local inflammation and infection contribute to tissue necrosis with risk for mucosal micro- or macroperforation.
  • Most right-sided diverticula are true diverticula (all layers of the colonic wall).
  • Most left-sided diverticula are pseudodiverticula (outpouchings of the mucosa and submucosa only).
  • Surgical and autopsy studies show mycosis, a constellation of thickened circular muscle (pseudohypertrophy due to increased elastin in the taeniae), short taeniae, and luminal narrowing.
  • Diverticulitis: inflammation with lymphocytic infiltrate, ulceration, mucin depletion necrosis, Paneth cell metaplasia, and cryptitis
  • Alterations in intestinal microbiota contribute to chronic inflammation (1,2).
  • Diverticular disease and irritable bowel syndrome (IBS) may be on the same disease continuum.
  • No known genetic pattern
  • Asian and African populations have lower overall prevalence but develop diverticular disease with adoption of a Western lifestyle.
  • Age >40 years
  • Low-fiber diet
  • Sedentary lifestyle, obesity
  • Previous diverticulitis. Risk rises with the number of diverticula
  • Smoking increases the risk of perforation (1).
  • NSAIDs, steroids, and opiate analgesics increase risk for diverticular bleeding. Calcium channel blockers and statins appear to protect against diverticular bleeding.
High-fiber diet or nonabsorbable fiber (psyllium) (>30 g/day of fiber)
Connective tissue diseases, colon cancer, and inflammatory bowel disease
  • Diverticulosis
    • Exam may be completely normal.
    • May have intermittent distension or tympany
    • No signs of peritoneal inflammation
    • May have heme + stools
  • Diverticulitis
    • Abdominal tenderness usually localized to the LLQ.
    • Rebound tenderness, involuntary guarding, or rigidity (suggests peritoneal inflammation or potential bowel perforation)
    • Palpable mass in LLQ (20%) that is tender, firm, or fixed.
    • Abdominal distension and tympany
    • Bowel sounds hypoactive or could be high-pitched and intermittent if obstruction ensues
    • Rectal exam may reveal tenderness or mass.
    • Colovaginal, colovesical, and perirectal fistulae may be the initial manifestation (rarely).
IBS, lactose intolerance, carcinoma, inflammatory bowel disease, fecal impaction, incarcerated hernia, gallbladder disease, angiodysplasia, colitis, acute appendicitis, ectopic pregnancy
Initial Tests (lab, imaging)
  • WBC is normal in diverticulosis and up to 45% of cases of diverticulitis. As diverticulitis worsens, WBC typically elevated with left shift.
  • Hemoglobin normal (unless bleeding)
  • ESR elevated in diverticulitis
  • Urinalysis (UA) may show microscopic pyuria or hematuria.
  • Urine culture: usually normal. Persistent infection suspicious for colovesical fistula
  • Blood cultures positive in systemic cases of diverticulitis
  • Diverticulosis
    • Asymptomatic diverticulosis is a common incidental finding on routine colonoscopy.
  • Diverticulitis
    • Plain films of the abdomen (acute abdominal series—supine and upright) to assess for air under the diaphragm (bowel perforation) and signs of bowel obstruction (dilated loops of bowel)
    • CT scan with IV, oral, and rectal contrast to stage disease and map treatment plan (3)[A]
    • Ultrasound and magnetic resonance imaging are useful alternative.
    • Barium enema is not recommended due to risk of peritoneal extravasation.
  • Diverticular bleeding/hematochezia
    • Endoscopy is the test of choice to evaluate GI bleeding (4,5).
    • Angiography if bleeding obscures endoscopy or when endoscopy cannot visualize a source (4,5)
Diagnostic Procedures/Other
  • For evaluation of suspected diverticular bleeding
    • Place NG tube for lavage to exclude upper GI bleeding (4).
    • 99mTc-pertechnetate-labeled RBC scan (more sensitive) with follow-up angiography to localize bleeding (not studied in a comparison trial) (4,5)
  • For diverticulitis, gallium- or indium-labeled leukocytes to localize abscess (rarely used)
  • Diverticulosis: Outpatient therapy with fiber supplementation and/or bulking agents (psyllium) is recommended (preferably >20 to 30 g/day) (3)[A].
  • Uncomplicated diverticulitis: pain, tenderness, leukocytosis, but no toxicity or peritoneal signs;

    use oral antibiotics. 1-2% of subjects require hospitalization for toxicity, septicemia, peritonitis, or failure of symptoms to resolve. Up to 30% of patients may require surgery at first episode of diverticulitis. Recurrent bouts of diverticulitis increase need for surgical intervention.
  • Complicated diverticulitis: Hinchey classification to describe severity:
    • Stage I: diverticulitis + confined paracolic abscess or phlegmon
    • Stage II: diverticulitis + distant abscess
    • Stage III: diverticulitis + purulent peritonitis
    • Stage IV: diverticulitis + fecal peritonitis
  • Patients who are septic or hemodynamically unstable require hospitalization, bowel rest, and broad-spectrum antibiotic therapy until symptoms improve.
  • Symptomatic improvement is expected within 2 to 3 days. Antibiotics should be continued for 7 to 10 days.
  • 80% of diverticular bleeding resolves spontaneously (4).
First Line
  • Symptomatic uncomplicated diverticular disease: cyclical rifaximin 400 mg PO BID for 7 days every month or continuous mesalamine 800 mg PO BID (3)[B]
  • Diverticulitis
    • Outpatient: PO antibiotics: cover for anaerobes and gram-negatives with:
      • A fluoroquinolone (ciprofloxacin 750 mg BID or levofloxacin 750 QD) plus metronidazole 500 mg TID (may use clindamycin if metronidazole intolerant) or
      • Trimethoprim/sulfamethoxazole DS BID plus metronidazole 500 TID
      • Treat for 7 to 10 days
    • The routine use of antibiotics in uncomplicated diverticulitis is controversial (6)[A].
    • Inpatient: Use IV antibiotics.
      • Monotherapy with a &bgr;-lactam/&bgr;-lactamase inhibitor: piperacillin/tazobactam (3,375 g IV QID) or ampicillin/sulbactam 3 g IV q6h or ertapenem (1 g IV QD)
      • Penicillin-allergic patient: quinolone (levofloxacin 750 mg IV QD plus metronidazole 500 mg IV TID)
      • Unresponsive or severe disease: imipenem or meropenem
    • Recurrences of acute diverticulitis may be decreased by using mesalamine ± rifaximin (7) [A] or probiotics.
  • Diverticular bleeding
    • Consider vasopressin 0.2 to 0.3 units/min through selective intra-arterial catheter.
  • Precautions
    • Avoid morphine and other opiates that may increase intraluminal pressure or promote ileus.
    • Increased fiber intake is not recommended in the acute management of diverticulitis.
Second Line
  • Outpatient: amoxicillin/clavulanate monotherapy (875/125 mg BID) (contraindicated in patients with clearance <30 mL/min) or moxifloxacin (400 mg PO QD) plus metronidazole (500 mg PO TID)
  • Severely ill inpatients: ampicillin (500 mg IV q6h) + metronidazole (500 mg IV TID) + a quinolone or ampicillin + metronidazole + an aminoglycoside
  • After resolution of diverticulitis, (typically 6 to 8 weeks), perform colonoscopy to exclude malignancy, fistula, strictures, or inflammatory bowel disease (3).
  • Patients with complicated diverticulitis (hemodynamic instability or failure to respond to initial IV antibiotic therapy) should have appropriate surgical and critical care/infectious disease consultations.
  • Indication for emergent surgery: peritonitis, uncontrolled sepsis, perforated viscus, colonic obstruction, or acute deterioration
  • Elective resection in nonemergent or recurrent cases of diverticulitis is a case-by-case decision (3)[B]:
    • After first episode of diverticulitis, there is a 33% chance of recurrence. After a second episode, there is a 66% chance of further recurrence.
    • Most complications occur during first bout of diverticulitis.
    • Emergent surgery carries a much higher risk of morbidity/mortality.
    • Recommendations for elective surgery are based on severity of complications (not solely on number of recurrences).
    • Elective resection is typically advised after recovery from a complicated diverticulitis treated nonoperatively (3)[B].
    • Younger patients are more likely to have recurrence.
    • Immunocompromised patients are more likely to present with acute complicated diverticulitis, fail medical management, and have complications from elective surgery.
  • Large abscesses (>4 cm) can be drained using radiographic guidance and managed nonoperatively (3).
  • Diverticular bleeding
    • Endoscopy and hemostasis by epinephrine injection, electrocautery, or clipping can be achieved (5).
    • Angiography can identify bleeding source and embolize the feeding artery (5).
    • Patient with massive bleeding and recurrent bleeding requires limited or subtotal colonic resection.
Probiotics such as Lactobacillus casei and Escherichia coli Nissle 1917 have been used with mixed success to prevent recurrence.
Admission Criteria/Initial Stabilization
  • Admit for toxicity, sepsis, and/or peritonitis.
  • Admit patients who cannot tolerate oral intake or who need IV fluids, analgesics, antibiotics, bowel rest, and NG suction.
  • NPO during acute diverticulitis; advance diet as tolerated as bowel function returns
  • Patients with known diverticulosis or a history of diverticulitis should consume a high-fiber diet (>30 g/day) to prevent recurrence (8).
  • Typically good with early detection and prompt treatment
  • Risk for recurrence increases with each subsequent bout of diverticulitis.
  • Rebleeding occurs in up to 6%.
  • Diverticulitis recurs more often in younger patients, but severity is similar to elderly.
1. Strate LL, Modi R, Cohen E, et al. Diverticular disease as a chronic illness: evolving epidemiologic and clinical insights. Am J Gastroenterol. 2012;107(10):1486-1493.
2. Sheth AA, Longo W, Floch MH. Diverticular disease and diverticulitis. Am J Gastroenterol. 2008;103(6):1550-1556.
3. Rafferty J, Shellito P, Hyman NH, et al. Practice parameters for sigmoid diverticulitis. Dis Colon Rectum. 2006;49(7):939-944.
4. Zuccaro G Jr. Management of the adult patient with acute lower gastrointestinal bleeding. American College of Gastroenterology. Practice Parameters Committee. Am J Gastroenterol. 1998;93(8):1202-1208.
5. Ghassemi KA, Jensen DM. Lower GI bleeding: epidemiology and management. Curr Gastroenterol Rep. 2013;15(7):333.
6. Shabanzadeh DM, Wille-Jørgensen P. Antibiotics for uncomplicated diverticulitis. Cochrane Database Syst Rev. 2012;(11):CD009092.
7. Gatta L, Vakil N, Vaira D, et al. Efficacy of 5-ASA in the treatment of colonic diverticular disease. J Clin Gastroenterol. 2010;44(2):113-119.
8. Ravikoff JE, Korzenik JR. Presentations the role of fiber in diverticular disease. J Clin Gastroenterol. 2011;45:S7-S11.
Additional Reading
  • Boynton W, Floch M. New strategies for the management of diverticular disease: insights for the clinician. Therap Adv Gastroenterol. 2013;6(3): 205-213.
  • Katz LH, Guy DD, Lahat A, et al. Diverticulitis in the young is not more aggressive than in the elderly, but it tends to recur more often: systematic review and meta-analysis. J Gastroenterol Hepatol. 2013;28(8): 1274-1281.
  • Templeton AW, Strate LL. Updates in diverticular disease. Curr Gastroenterol Rep. 2013;15(8):339.
  • K57.90 Dvrtclos of intest, part unsp, w/o perf or abscess w/o bleed
  • K57.30 Dvrtclos of lg int w/o perforation or abscess w/o bleeding
  • K57.92 Diverticulitis of intestine, part unspecified, without perforation or abscess without bleeding
Clinical Pearls
  • Diverticular disease is age-related and more common in Western cultures due to diet and lifestyle.
  • Patients with known diverticular disease should consume a high-fiber diet (>30g/day).
  • Decision for elective surgery in diverticulitis is made on a case-by-case basis.