Colo-splenic fistula and generalized purulent peritonitis complicating Crohn’s disease: a case report

Background: Splenic abscesses are rare clinical entities, with an incidence of 0.1–0.7%. While fistulization is a well-known complication of Crohn’s disease (CD), colosplenic fistula (CSF) formation leading to splenic abscess and secondary peritonitis remains exceptionally rare. Case presentation: A 38-year-old male with a known history of colonic CD (diagnosed in September 2024, maintained on azathioprine following steroid-induced remission, but non-compliant due to gastrointestinal intolerance) presented in April 2025 with fever (38.7°C) and right-sided abdominal pain. Abdominopelvic CT revealed severe left-sided colitis complicated by gas-containing splenic abscesses fistulizing into the splenic flexure, along with early hepatic suppurative foci. Initial CT-guided percutaneous drainage and antibiotic therapy were initiated as a bridge to elective surgery. However, clinical deterioration with left hypochondrial peritoneal signs dictated emergent exploratory laparotomy. Intraoperative findings confirmed generalized purulent peritonitis and a severely inflamed colonic splenic flexure fistulizing into a gangrenous, enlarged spleen. Left hemicolectomy, splenectomy, abscess debridement, and a double-barrel colostomy (Bouilly–Volkmann procedure) were performed. Postoperative recovery was uneventful; the patient was discharged on day 7 with long-term targeted antibiotics and post-splenectomy immunization. Conclusion: CSF is a rare intra-abdominal septic complication of CD. While preoperative optimization with percutaneous drainage and medical therapy is ideal for bowel preservation, emergent surgical intervention remains essential in the setting of impending septic decompensation or peritonitis.