Vaso-Occlusive Thrombotic Ischemic Colitis Presenting With Large-Volume Hematochezia in Sickle Cell Beta+-Thalassemia.

We present the case of a 60-year-old African American man with sickle cell beta plus thalassemia who developed large-volume hematochezia during hospitalization for a vaso-occlusive crisis. Sickle cell disease is characterized by chronic hemolysis and vaso-occlusion that can affect the gastrointestinal tract, although clinically significant colonic ischemia remains rare. The patient had a history of diverticulosis and hemorrhoids but presented with acute lower gastrointestinal bleeding after dehydration and nonsteroidal anti-inflammatory drug exposure, both of which can impair mucosal perfusion. Colonoscopy revealed discontinuous ulcerations in the rectosigmoid colon, and histopathology confirmed ischemic colitis with thrombosed submucosal vessels, consistent with vaso-occlusive microthrombosis. This case underscores the importance of early endoscopic evaluation and recognition of ischemic colitis as a potential cause of overt gastrointestinal bleeding in patients with sickle cell disease.