Rectosigmoid intussusception through the anus mimicking rectal prolapse.

Intussusception of the colon usually occurs in infants and children. Although rectal prolapse is not uncommon, presentation of more proximal segments of large bowel through the anus is extremely rare. We report two cases of rectosigmoid intussusception in which sigmoid colon intussusception was diagnosed as rectal prolapse preoperatively.