Differential Diagnosis for Post-Operative Fever and Abdominal Distention

• Single most likely diagnosis:
  • Anastomotic leak: This is a common complication after colostomy closure, especially in patients with a history of imperforate anus and previous surgeries. The presentation of fever and abdominal distention 5 days post-operatively is consistent with an anastomotic leak, which can lead to peritonitis and sepsis if not promptly addressed.
• Other Likely diagnoses:
  • Surgical site infection: While less likely than an anastomotic leak given the timing and symptoms, surgical site infections can occur after any surgical procedure and may present with fever and abdominal distention.
  • Ileus: Post-operative ileus is a common complication after abdominal surgery, which can cause abdominal distention. However, the presence of fever might suggest an infectious or inflammatory cause rather than a pure ileus.
• Do Not Miss diagnoses:
  • Septic peritonitis: This is a life-threatening condition that can arise from an anastomotic leak or a surgical site infection. Prompt recognition and treatment are crucial to prevent high morbidity and mortality.
  • Bowel obstruction: Although less common in this context, bowel obstruction can cause abdominal distention and fever if there is associated bowel ischemia. It's a critical diagnosis to consider because it requires urgent intervention.
• Rare diagnoses:
  • Intra-abdominal abscess: While possible, an intra-abdominal abscess might be less likely at this early stage post-operatively without a clear source of infection or a history of previous abscesses.
  • Adhesive disease: Although rare at this stage, adhesive disease leading to bowel obstruction can occur after any abdominal surgery. However, the presence of fever would be unusual unless there was associated bowel ischemia or infection.