What is the best course of treatment for a patient with a history of diverticulitis, now presenting with intermittent right-sided abdominal pain, after a previous diagnosis of perforated acute diverticulitis and conservative management?

Management of Intermittent Right-Sided Abdominal Pain After Perforated Diverticulitis

This patient requires repeat CT imaging to evaluate for ongoing complications, followed by consideration of the probable cholelithiasis as the source of right-sided pain, since the previous diverticulitis was in the descending colon (left-sided) and has been managed conservatively with normal follow-up endoscopy.

Initial Diagnostic Approach

The key issue here is that the patient's current right-sided abdominal pain is anatomically discordant with the previous left-sided (descending colon) perforated diverticulitis 1. This geographic mismatch is critical and suggests an alternative diagnosis.

Imaging Evaluation

• CT abdomen/pelvis with IV contrast should be obtained to exclude ongoing diverticular complications (abscess, fistula, stricture) or alternative diagnoses, particularly in patients who fail to improve with therapy or have recurrent symptoms 1
• CT has 95% sensitivity and specificity for diagnosing diverticulitis and its complications 1
• The imaging is essential to differentiate between ongoing diverticular inflammation versus the probable cholelithiasis noted on the initial scan 1

Endoscopic Considerations

• The patient has already undergone colonoscopy/endoscopy which was normal, appropriately performed after the acute episode 1
• Since the endoscopy was normal and this is a new symptom pattern (right-sided vs. left-sided), repeat endoscopy is not immediately indicated unless alarm symptoms develop 1

Differential Diagnosis Priority

Most Likely: Biliary Pathology

• The right-sided location strongly suggests the probable cholelithiasis identified on initial CT as the culprit 1
• Intermittent right upper quadrant/right-sided pain with normal bowel movements and gas passage is classic for biliary colic 1
• Obtain right upper quadrant ultrasound to evaluate for acute cholecystitis, choledocholithiasis, or biliary colic 1

Less Likely: Diverticular-Related

• Right-sided diverticulitis is uncommon in Western populations (more common in Asian populations) and would represent new disease, not recurrence of the descending colon perforation 2
• The previous perforated diverticulitis was successfully managed conservatively with normal follow-up endoscopy, making active diverticular disease less likely 1

Consider: Post-Diverticulitis Visceral Hypersensitivity

• Approximately 45% of patients report periodic abdominal pain at 1-year follow-up after acute diverticulitis 1
• However, visceral hypersensitivity typically manifests in the same anatomic location as the original inflammation (left-sided in this case) 1
• If imaging and workup are negative, visceral hypersensitivity can be managed with low-dose tricyclic antidepressants 1

Management Algorithm

Step 1: Immediate Workup

• CT abdomen/pelvis with IV contrast to evaluate for:
  • Diverticular complications (abscess, fistula, stricture) 1
  • Alternative diagnoses 1
• Right upper quadrant ultrasound specifically for biliary pathology 1
• Laboratory studies: CBC, CMP, liver function tests, lipase 3

Step 2: Based on Imaging Results

If biliary pathology confirmed:

• Surgical consultation for cholecystectomy if acute cholecystitis 1
• ERCP if choledocholithiasis suspected 1

If new diverticular complication identified:

• Complicated diverticulitis requires IV antibiotics (ceftriaxone plus metronidazole or piperacillin-tazobactam) 4
• Abscess >4 cm requires percutaneous drainage 5, 4
• Generalized peritonitis requires emergent laparotomy 5, 4

If imaging negative:

• Consider visceral hypersensitivity and treat with reassurance and low-dose tricyclic antidepressant if needed 1
• Ensure high-fiber diet for long-term diverticular disease management 3, 2

Critical Pitfalls to Avoid

• Do not assume right-sided pain is related to left-sided diverticulitis - the anatomy doesn't match 2
• Do not ignore the incidental finding of cholelithiasis - this is the most anatomically consistent explanation for right-sided pain 1
• Do not repeat colonoscopy without indication - it was already performed and was normal 1
• Do not empirically treat with antibiotics without imaging confirmation of active infection 4, 3

When to Escalate Care

• Development of fever, peritoneal signs, or hemodynamic instability requires immediate surgical consultation 5, 4
• Persistent or worsening symptoms despite appropriate management warrant repeat imaging 1
• Immunocompromised patients or those with significant comorbidities have lower threshold for intervention 4, 2