Protruded-type mucosal prolapse syndrome in a young patient

A 16-year-old boy was referred to our hospital because he had experienced bloody diarrhea for 1 year. His diarrhea occurred 3 times a day, and he had strained during defecation in the bathroom for at least 15 minutes every time over the previous 3 years. Proctoscopy showed a reddish protruded rectal tumor. Colonoscopy also showed a protruded lesion with erythema and erosion at the center of the anterior wall over three-quarters of the lower...