Regeneration of rectal mucosa and recurrent polyposis coli after total colectomy and ileoanal anastomosis.

Two patients with adenomatous polyposis of the colon who had been treated by colectomy, stripping of rectal mucosa, transrectal pull-through of terminal ileum, and ileoanal anastomosis were found--after seven and three years--to have recurrent polyposis in the rectal segment, consequent to regeneration of the rectal mucosa. The latter might have resulted form retraction of the implanted ileum or sloughing of its mucosa, followed by upward growth of epithelium from the strip of anal mucosa retained above the dentate line at the time of surgery. Colonic metaplasia of the implanted ileal mucosa may be an alternative explanation. In all patients who have had this operation for polyposis coli, the rectal segment should be reexamined by endoscopy and biopsy to rule out recurrent polyposis or replacement of ileal mucosa by colorectal mucosa.