Fulminant Ischemic Colitis With Toxic Megacolon in a Young Man Receiving Testosterone Replacement Therapy Despite Therapeutic Phlebotomy for Hereditary Hemochromatosis: A Case Report

Fulminant ischemic colitis with toxic megacolon requiring emergent colectomy is uncommon in younger adults and warrants evaluation for unusual etiologies and potentially modifiable risk factors.Testosterone replacement therapy (TRT) is a recognized cause of secondary erythrocytosis, while acute volume depletion and systemic hypoperfusion may further compromise mesenteric perfusion.We report the case of a 43-year-old man with hereditary hemochromatosis managed with therapeutic phlebotomy, hypogonadism treated with intramuscular testosterone, type 2 diabetes mellitus, stage 3a chronic kidney disease, hyperlipidemia, obesity, and active tobacco use who presented with three days of progressive abdominal distention, markedly decreased oral intake, severe abdominal pain, and syncope.Laboratory evaluation demonstrated erythrocytosis, with a hemoglobin of 17.9 g/dL and hematocrit of 52.2% despite therapeutic phlebotomy 13 days earlier, along with severe hyperglycemia and renal dysfunction in a clinical context supportive of volume depletion.Computed tomography demonstrated diffuse colonic dilation and pneumatosis involving the ascending colon.Emergent exploratory laparotomy revealed toxic megacolon with extensive necrotic changes extending from the cecum to the proximal descending colon of unclear etiology, requiring subtotal colectomy with end ileostomy.Surgical pathology demonstrated mucosal hemorrhage and focal transmural acute inflammation, with viable resection margins and no evidence of malignancy.An extensive thrombophilia evaluation was unrevealing, including testing for Factor V Leiden, prothrombin G20210A mutation, antiphospholipid antibodies, lupus anticoagulant, antithrombin deficiency, and protein S deficiency.Following discharge, erythrocytosis persisted despite recent phlebotomy, with hemoglobin 17.1 g/dL and hematocrit 51%.This case highlights a potentially multifactorial pathway to severe colonic ischemia involving persistent erythrocytosis during testosterone therapy, acute volume depletion, severe colonic distention, and underlying vascular risk factors.Although causality between TRT-associated erythrocytosis and colonic ischemia cannot be established, the combination may have contributed to impaired microvascular perfusion in a susceptible patient.The case emphasizes the importance of monitoring hematocrit in patients receiving testosterone therapy, particularly when additional risk factors for hypoperfusion or thrombosis are present, and highlights the importance of coordinated postoperative care to ensure timely access to essential ostomy supplies.