Life-Threatening Haemorrhagic Enterocolitis: A Rare Complication of Chemotherapy With Cyclophosphamide.

Cyclophosphamide (CPA) is a commonly used alkylating agent with its use extending from chemotherapy to immunosuppression. Herein, we present a case of a 61-year-old lady diagnosed with Sjögren's syndrome one year ago, who recently started on CPA therapy and presented to ICU with the sudden onset of bloody diarrhoea and shock, requiring fluid resuscitation and vasopressor support. An extensive evaluation, including stool routine analysis, cultures, stool BioFire® FilmArray® (gastrointestinal panel) (BioFire Diagnostics, LLC, Salt Lake City, USA), contrast-enhanced CT (CECT) of the abdomen, colonoscopy, and biopsy, ruled out infectious, inflammatory, ischemic, and malignant causes. After discontinuation of CPA and supportive therapy, her clinical condition improved, and she was discharged. Haemorrhagic cystitis, myelosuppression, gonadal toxicity and interstitial pneumonia are well-known side effects of CPA. Haemorrhagic enterocolitis is a rare adverse effect of CPA therapy. Through this case report, we aim to highlight that haemorrhagic enterocolitis can be a potentially life-threatening adverse effect of CPA, a drug widely used in rheumatological and oncological conditions. Increased awareness among treating physicians can help in early suspicion and appropriate management, including prompt discontinuation of the drug and consideration of alternative treatment options.