pathogenesis
Last reviewed 01/2018
A rectal prolapse is in effect a hernia of the rectum through the floor of the pelvis. The mucosa and muscle wall of the rectum intussuscept through the anal canal. Contributory factors include denervation of the puborectalis muscle, loss of the acute anorectal angle, and poor fixation of the rectum to the sacrum.
Early on in the condition, prolapse only occurs with defaecation and retracts spontaneously. As the condition worsens, rectal prolapse may occur with only slight increases in intra-abdominal pressure, e.g. when the patient stands up.