Diverticulitis with coloenteric fistula mimicking gangrenous appendicitis with perityphlitic abscess. An uncommon presentation of a common disease – A case report

INTRODUCTION: Diverticulitis is a common gastrointestinal disease usually presenting with a typical clinical picture depending on the stage of the disease. In complicated cases, the clinical presentation may be untypical, thus delaying diagnosis and treatment. PRESENTATION OF CASE: We present a case of a young patient who was initially treated for obscure intraabdominal abscesses presumably due to gangrenous appendicitis; however, intraoperative exploration revealed a normal appendix and a coloenteric fistula resulting from an unknown and untreated perforated diverticulitis. DISCUSSION: A patient with a perityphlitic abscess was initially managed with primary non-operative management (NOM) in accordance with the current Jerusalem guidelines, but surgery was eventually necessary due to failure of NOM. Intraoperative findings revealed a sigmoido-ileal fistula, a rare but potentially detectable complication of diverticulitis through colonoscopy. This case highlights the challenges in diagnosing and treating common surgical diseases with uncommon clinical presentations, emphasizing the importance of a detailed patient history and not relying solely on imaging studies. CONCLUSION: Intraabdominal abscesses require prompt treatment with non-operative management, while intestinal fistulae associated with diverticulitis are a rare consequence of chronic inflammation, often asymptomatic and often detected incidentally during surgery. In most cases simple fistulous tract resection is usually sufficient as first line therapy.