Electronic Clinical Challenges and Images in GI An Unusual Cause of Lower GI Bleeding

Question: A 17-yearold boy living in a tropical country presented with easy fatigability and bloody stools of 2 months’ duration. He did not have fever or tenesmus. He was undernourished and clinical examination revealed significant pallor with koilonychia. Laboratory investigations showed iron deficiency anemia with the hemoglobin of 6.5 g/mL. HIV serology was nonreactive. Colonoscopy examination showed the following picture (Figures A, B). What is the diagnosis? See the GASTROENTEROLOGY web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.