Deviation of the rectosigmoid colon simulating a presacral tumor: report of a case.

The rectosigmoid colon has a potential for a great deal of mobility and variation of position. This is partially due to the wide variation in length and distal attachment of the sigmoid mesocolon. When anterior or lateral deviations of the distal sigmoid and rectum are found on barium-enema examinations, the possibility of anomalous fixation of the rectosigmoid should be considered.