Diagnosis

Diverticulitis

Etiology

Cause

• Bacterial infection from the colon flora

Pathophysiology [kgs]

1. Diverticula: herniation of the mucosa through the muscular layers of the bowel wall at sites where arterioles penetrate

2. Diverticula can occur anywhere in the GI tract but are usually observed in the colon

3. The sigmoid colon has the highest intraluminal pressures and is most commonly affected.

4. Fecal material may collect in a diverticulum --> obstruction

5. Mucous secretion --> distension of the diverticula

6. Overgrowth of normal colonic bacteria --> Diverticulitis

7. Vascular compromise --> perforation

   • Walled-off perforation: microperforation contained by nearby omentum, fat, and inflamed tissue --> preventing fecal contamination into the abdominal cavity

   • Larger perforations --> abscess and peritonitis

Risk factors [kgs]

• Red meat

• Obesity

• Smoking

• Alcohol

• Medications: NSAIDs, aminosalicylates, acetaminophen, corticosteroids

Complications [kgs]

• Cancer

• Perforation

• Abscess

• Sepsis

• Fistula (colovesical, colovagnial)

• Strictures/obstruction

Epidemiology

Incidence per 100.000 [hoq][6bi][hwk][oqe][tfh]

Approach

• Blood test

• Abdominal x-ray

• CT abdomen

• Barium enema

• Colonoscopy

Treatment

1. Segmental colitis associated with diverticula: [hwk]

   • Chronic abdominal pain, particularly left sided

   • Occasional hematochezia

   • Indistinguishable from inflammatory bowel disease

   • May progress to develop Crohn’s disease or ulcerative colitis

   • Treatment: 5-aminosalicylates or resection

2. Uncomplicated diverticulitis: 75% of the cases

   • Clear fluids/bowel rest

   • Pain control

   • Antibiotics:

     • Oral ciprofloxacin, metronidazole, amoxicillin/clavulanate

     • Hospitalized patients --> intravenous broad-spectrum ceftriaxone and metronidazole, piperacillin/tazobactam, meropenem

     • 33% will experience recurrence of diverticulitis --> consider elective resection

     • Colonoscopy in 4-6 weeks (if 1st episode) to exclude cancer

3. Complicated diverticulitis: 25% (Perforation, abscess, fistula, strictures/obstruction)

   • Small abscesses (<3 cm) --> antibiotics

     • Larger abscesses (>4 cm) --> CT-guided percutaneous drainage, antibiotics or surgery

     • Fistula --> resection

     • Recurrent diverticulitis --> fibrosis/stricturing/obstruction (cancer?) --> endoscopic dilation or resection

     • Perforation and peritonitis --> urgent resection (Hartmann’s procedure)

Differential diagnoses

Abdominal abscess, Acute mesenteric ischemia, Acute pancreatitis, Adhesion, Appendicitis, Benign neoplasm of the small intestine, Biliary obstruction, Cholangitis, Cholecystitis, Cholelithiasis, Chronic mesenteric ischemia, Colorectal cancer, Colovesical fistula, Constipation, Crohn disease, Femoral hernia, Gastritis, Gastroenteritis, Gastrointestinal obstruction, Gastrointestinal perforation, Incisional hernia, Infectious colitis, Inguinal hernia, Intussusception, Irritable bowel syndrome, Ischemic colitis, Liver abscess, Meckels diverticulum, Ovarian torsion, Pelvic inflammatory disease, Perforated ulcer, Peritonitis, Pyelonephritis, Rectovaginal fistula, Ruptured ectopic pregnancy, Ruptured ovarian cyst, Small bowel cancer, Ulcerative colitis, Ulcer disease, Umbillical hernia, Urinary retention, Urinary tract infection, Urolithiasis, Volvulus