Histoplasmosis is the most common endemic mycosis in the United States. Symptomatic gastrointestinal histoplasmosis is a rare entity. We report a case of isolated intestinal histoplasmosis that manifested as severe lower gastrointestinal bleeding in a renal transplant patient. The patient developed hematochezia, and colonoscopy showed diffuse, extensive areas of cratered, ulcerated mucosa in the entire colon. Biopsy showed prominent mucosal and submucosal infiltrate of plump histiocytes containing intracytoplasmic yeast forms morphologically compatible with florid histoplasmosis.