As a surgery resident, how should I manage a patient with diverticulitis complicated by transient physiologic intussusception?

Management of Physiological Intussusception in the Setting of Diverticulitis

Physiological (transient) intussusception discovered incidentally during imaging for diverticulitis requires no specific intervention—focus entirely on treating the underlying diverticulitis according to standard protocols. 1

Understanding the Clinical Context

Transient intussusception in adults is fundamentally different from pediatric intussusception and rarely causes obstruction or ischemia. In the setting of acute diverticulitis, any intussusception visualized on CT is almost always a physiological, self-resolving phenomenon related to bowel wall edema and inflammation rather than a pathological lead point requiring surgical correction. 2

• The key distinction: Pathological intussusception in adults is typically caused by malignant tumors or polyps and presents with obstructive symptoms, whereas physiological intussusception is asymptomatic and discovered incidentally on imaging. 2

• In diverticulitis specifically: Bowel wall thickening, pericolic inflammation, and localized edema can create transient telescoping of bowel segments that resolves spontaneously as the inflammation subsides. 2

Diagnostic Approach

Obtain contrast-enhanced CT of the abdomen and pelvis to confirm the diagnosis of diverticulitis and assess for complications—this same imaging will characterize any intussusception. 1

• CT findings to document: Extent of bowel wall thickening, presence of pericolic fat stranding, any abscess formation (size and location), extraluminal air, and the appearance of intussusception (target sign or bowel-within-bowel configuration). 1

• Red flags requiring immediate surgical consultation: Signs of bowel obstruction (dilated proximal bowel, air-fluid levels, inability to pass flatus for >72 hours), ischemia (pneumatosis intestinalis, portal venous gas), or hemodynamic instability. 1, 3

Management Algorithm

Step 1: Classify the Diverticulitis

Use CT findings to determine whether the diverticulitis is uncomplicated (localized inflammation only) or complicated (abscess, perforation, fistula, obstruction). 1, 4

• Uncomplicated diverticulitis: No abscess, no perforation, no extraluminal air beyond the pericolic region, no obstruction. 1, 4

• Complicated diverticulitis: Abscess ≥4–5 cm, free perforation with distant intraperitoneal air, generalized peritonitis, or bowel obstruction. 1, 3

Step 2: Determine Inpatient vs. Outpatient Management

Admit to the hospital if any of the following are present: complicated diverticulitis on CT, inability to tolerate oral intake, temperature >100.4°F, severe pain (≥8/10), immunocompromised status (chemotherapy, high-dose steroids, organ transplant), significant comorbidities (cirrhosis, CKD, heart failure, poorly controlled diabetes), age >80 years, or pregnancy. 1, 4

• Outpatient management is appropriate only if all criteria are met: CT-confirmed uncomplicated disease, ability to tolerate oral fluids and medications, temperature <100.4°F, pain controlled with acetaminophen alone (score <4/10), immunocompetent status, no significant comorbidities, and reliable follow-up within 7 days. 1, 4

Step 3: Antibiotic Decision

For immunocompetent patients with uncomplicated diverticulitis, observation without antibiotics is first-line—reserve antibiotics only for high-risk features. 1, 4

• High-risk features mandating antibiotics: Persistent fever or chills, refractory symptoms or vomiting, inability to maintain oral hydration, symptom duration >5 days, CRP >140 mg/L, WBC >15 × 10⁹/L, CT evidence of fluid collection or extensive inflammation, immunocompromised status, age >80 years, pregnancy, or ASA score III–IV. 1, 4

• Outpatient oral regimen (4–7 days): Amoxicillin-clavulanate 875/125 mg twice daily OR ciprofloxacin 500 mg twice daily PLUS metronidazole 500 mg three times daily. 1, 4

• Inpatient IV regimen: Ceftriaxone PLUS metronidazole OR piperacillin-tazobactam; transition to oral antibiotics within 48 hours once the patient tolerates oral intake. 1, 4

• Duration: 4–7 days for immunocompetent patients; 10–14 days for immunocompromised patients. 1, 4

Step 4: Supportive Care

Initiate bowel rest with a clear liquid diet for 2–3 days during the acute phase, then advance as tolerated. 4

• Pain management: Acetaminophen 1 g three times daily; avoid NSAIDs as they increase the risk of perforation. 1, 4

• Hydration: Ensure adequate oral or IV fluid intake to maintain urine output and prevent dehydration. 1

Step 5: Monitor for Treatment Failure

Re-evaluate the patient within 7 days of diagnosis (earlier if symptoms worsen). 1, 4

• Signs of treatment failure requiring repeat CT imaging: Persistent fever beyond 48–72 hours, worsening abdominal pain, new inability to tolerate oral intake, rising leukocytosis, or persistent tachycardia despite adequate resuscitation. 1, 3, 5

• Indications for urgent surgical consultation: Development of generalized peritonitis (diffuse rigidity, rebound tenderness), hemodynamic instability, septic shock, or failure of medical management after 5–7 days of appropriate antibiotics. 1, 3, 5

Specific Management of Complicated Diverticulitis

For small abscesses (<4–5 cm), treat with IV antibiotics alone for 7 days. 1, 3

For large abscesses (≥4–5 cm), perform CT-guided percutaneous drainage PLUS IV antibiotics; continue antibiotics for 4 days post-drainage in immunocompetent patients. 1, 3

For generalized peritonitis or sepsis, obtain emergent surgical consultation for source control (Hartmann procedure or primary resection with anastomosis) and start broad-spectrum IV antibiotics immediately. 1, 3, 5

When to Address the Intussusception Surgically

Surgical intervention for intussusception is indicated ONLY if it causes mechanical bowel obstruction that does not resolve with conservative management of the diverticulitis. 2

• Criteria for surgical consideration: Persistent inability to pass flatus or stool for >72 hours despite treatment, progressive abdominal distention, CT evidence of high-grade obstruction with dilated proximal bowel, or signs of bowel ischemia (pneumatosis, portal venous gas, peritonitis). 3, 5, 2

• Surgical approach if required: Laparoscopic or open right colectomy (if cecal/ascending colon involvement) or segmental resection of the affected bowel segment with primary anastomosis. 2

• Expected outcome: In the vast majority of cases, the intussusception resolves spontaneously as the diverticulitis improves, and no specific surgical intervention for the intussusception itself is needed. 2

Post-Acute Management

Schedule colonoscopy 6–8 weeks after symptom resolution for any complicated diverticulitis episode or first episode of uncomplicated diverticulitis (if no recent high-quality colonoscopy). 1, 4

• Rationale: Approximately 7.9% of complicated diverticulitis cases harbor an underlying colorectal carcinoma; colonoscopy is essential to exclude malignancy. 1, 4, 5

Counsel the patient on lifestyle modifications to prevent recurrence: high-fiber diet (≥22 g/day from fruits, vegetables, whole grains, legumes), regular vigorous physical activity, maintaining BMI 18–25 kg/m², smoking cessation, and avoiding NSAIDs when possible. 1, 4

Critical Pitfalls to Avoid

• Do not assume the intussusception requires surgical correction simply because it is present on imaging—treat the diverticulitis and reassess. 2

• Do not perform colonoscopy during the acute inflammatory phase; this carries a high risk of perforation and does not alter acute management. 4, 5

• Do not prescribe routine antibiotics for uncomplicated diverticulitis without high-risk features; this contributes to antimicrobial resistance without clinical benefit. 1, 4

• Do not discharge patients with complicated diverticulitis (abscess, perforation, obstruction) for outpatient care; hospitalization is mandatory. 1, 3

• Do not delay surgical consultation if the patient develops generalized peritonitis, hemodynamic instability, or fails to improve after 5–7 days of appropriate medical management. 1, 3, 5