Diverticulitis 1. Bаckgrоund Definitiоn: Inflаmmаtiоn and microperforation of a colonic diverticulum, most commonly in the sigmoid colon. Pathophysiology: Diverticula form at weak points in the colonic wall where vasa recta penetrate the muscular layer (diverticulosis). Fecalith obstruction or microperforation → localized inflammation and infection = diverticulitis. Epidemiology: Common in adults >50 years. Risk factors: low-fiber diet, obesity, physical inactivity, NSAID use, and advancing age. Complications: Abscess, perforation, peritonitis, fistula (colovesical most common), or obstruction. 2. History Symptoms: Left lower quadrant (LLQ) abdominal pain (most common). Fever, nausea/vomiting, change in bowel habits (constipation or diarrhea). Urinary symptoms (dysuria, pneumaturia) may indicate colovesical fistula. History clues: Prior episodes suggest recurrent diverticulitis. Use of NSAIDs or opioids may increase risk of complications. 3. Exam Findings Typical: LLQ tenderness, low-grade fever, mild distension. Possible: Palpable mass (abscess), guarding, or rebound tenderness if perforation or peritonitis. Rectal exam: May show occult blood; gross bleeding is rare. Severe findings: Tachycardia, hypotension (suggest complicated diverticulitis). 4. Making the Diagnosis Gold standard imaging: CT abdomen and pelvis with IV contrast — shows colonic wall thickening, fat stranding, and possible abscess or perforation. Laboratory: Leukocytosis, elevated CRP. Plain X-ray: May show ileus or free air if perforation. Avoid colonoscopy or barium enema during acute episode due to risk of perforation. Colonoscopy recommended 6–8 weeks after recovery to exclude malignancy. 5. Management A. Uncomplicated Diverticulitis Outpatient treatment: Clear liquid diet → advance as tolerated. Oral antibiotics covering gram-negative and anaerobes (e.g., amoxicillin–clavulanate or ciprofloxacin + metronidazole). Close follow-up within 2–3 days. Inpatient indications: Severe pain, high fever, vomiting, leukocytosis, immunosuppression, or inability to tolerate PO intake. B. Complicated Diverticulitis IV antibiotics and hospitalization. CT-guided percutaneous drainage for abscess >3 cm. Surgical intervention for perforation, peritonitis, obstruction, or recurrent complicated episodes (possible sigmoid colectomy). C. Prevention High-fiber diet, adequate hydration, weight control, and avoidance of NSAIDs. Question A 56-year-old woman presents with 2 days of constant left lower quadrant abdominal pain and mild fever. She reports nausea but no vomiting and is tolerating oral fluids. Her vital signs are stable. Physical examination shows localized left lower quadrant tenderness without guarding or rebound. Laboratory studies reveal a mild leukocytosis. CT of the abdomen and pelvis demonstrates localized sigmoid wall thickening and pericolic fat stranding without abscess or perforation. Which of the following is the most appropriate initial management for this patient?