Later, the mass may have to be pushed back in following defecation. This may progress to a chronically prolapsed and severe condition, defined as spontaneous prolapse that is difficult to keep inside, and occurs with walking, prolonged standing, coughing or sneezing (Valsalva maneuvers). A chronically prolapsed rectal tissue may undergo pathological changes such as thickening, ulceration and bleeding.If the prolapse becomes trapped externally outside the anal sphincters, it may become strangulated and there is a risk of perforation. This may require an urgent surgical operation if the prolapse cannot be manually reduced. Applying granulated sugar on the exposed rectal tissue can reduce the edema (swelling) and facilitate this. Cause
The precise cause is unknown, and has been much debated. In 1912 Moschcowitz proposed that rectal prolapse was a sliding hernia through a pelvic fascial defect.This theory was based on the observation that rectal prolapse patients have a mobile and unsupported pelvic floor, and a hernia sac of peritoneum from the Pouch of Douglas and rectal wall can be seen. Other adjacent structures can sometimes be seen in addition to the rectal prolapse. Although a pouch of Douglas hernia, originating in the cul de sac of Douglas, may protrude from the anus (via the anterior rectal wall), this is a different situation from rectal prolapse. Shortly after the invention of defecography, In 1968 Broden and Snellman used cinedefecography to show that rectal prolapse begins as a circumferential intussusception of the rectum, which slowly increases over time.
Cystica profunda is characterized by formation of mucin cysts in the muscle layers of the gut lining, and it can occur anywhere along the gastrointestinal tract. When it occurs in the rectum, some believe to be an interchangeable diagnosis with SRUS since the histologic features of the conditions overlap. Indeed, CCP is managed identically to SRUS.Electromyography may show pudendal nerve motor latency. Complications
Complications are uncommon, but include massive rectal bleeding, ulceration into the prostate gland or formation of a stricture. Very rarely, cancer can arise on the section of prolapsed rectal lining. Diagnosis and investigations
SRUS is commonly misdiagnosed, and the diagnosis is not made for 5–7 years. Clinicians may not be familiar with the condition, and treat for Inflammatory bowel disease, or simple constipation.The thickened lining or ulceration can also be mistaken for types of cancer.The differential diagnosis of SRUS (and CCP) includes:
polyps
endometriosis
inflammatory granulomas
infectious disorders
drug-induced colitis
mucus-producing adenocarcinomaDefecography, sigmoidoscopy,  transrectal ultrasound, mucosal biopsy, anorectal manometry and electromyography have all been used to diagnose and study SRUS. Some recommend biopsy as essential for diagnosis since ulcerations may not always be present, and others state defecography as the investigation of choice to diagnose SRUS. Treatment
Although SRUS is not a medically serious disease, it can be the cause of significantly reduced quality of life for patients. It is difficult to treat, and treatment is aimed at minimizing symptoms. Stopping straining during bowel movements, by use of correct posture, dietary fiber intake (possibly included bulk forming laxatives such as psyllium), stool softeners (e.g.