True about solitary rectal ulcer syndrome is all/ except

Classically, it takes the form of an ulcer on the anterior wall of the rectum.ulceration may heal, leaving a polypoid appearance.A variety of explanations as to its cause has been suggested, including persistent trauma by anal digitation. However, recent proctographic studies indicate that it may be due to a combination of internal intussusception or anterior rectal wall prolapse and an increase in intrarectal pressure. This combination of factors is usually caused by chronic straining as a result of constipation Ref: Bailey & Love&;s Sho Practice of Surgery,E25,Page-1227