Eroded polypoid hyperplasia of the rectosigmoid.

We studied histologic sections and clinical data from six patients with multiple rectosigmoid polyps that could not be readily classified. Features common to all were: 1) numerous polyps restricted to the rectosigmoid colon without evidence of polyposis or gastrointestinal disease elsewhere, 2) severe clinical symptoms mimicking inflammatory bowel disease, 3) no family history of polyposis or evidence of infection and 4) histology showing minimally inflamed polypoid hyperplastic mucosa with surface erosions or pseudomembranes. Three patients underwent colectomies; three showed a response to oral steroids. One had rectal prolapse. Although reminiscent of inflammatory cloacogenic polyps or solitary rectal ulcer syndrome, the polyps extended into the sigmoid colon, were quite numerous, and showed only mild smooth muscle insinuation in the lamina propria. Whether these lesions are due to occult prolapse or are an unusual manifestation of inflammatory bowel disease remains unclear.