Proximal bilateral pudendal neuropathy has been demonstrated in patients with rectal prolapse who have fecal incontinence. This finding was shown to be absent in healthy subjects, and may be the cause of denervation-related atrophy of the external anal sphincter. Some authors suggest that pudendal nerve damage is the cause for pelvic floor and anal sphincter weakening, and may be the underlying cause of a spectrum of pelvic floor disorders.Sphincter function in rectal prolapse is almost always reduced. This may be the result of direct sphincter injury by chronic stretching of the prolapsing rectum. Alternatively, the intussuscepting rectum may lead to chronic stimulation of the rectoanal inhibitory reflex (RAIR - contraction of the external anal sphincter in response to stool in the rectum). The RAIR was shown to be absent or blunted. Squeeze (maximum voluntary contraction) pressures may be affected as well as the resting tone. This is most likely a denervation injury to the external anal sphincter.The assumed mechanism of fecal incontinence in rectal prolapse is by the chronic stretch and trauma to the anal sphincters and the presence of a direct conduit (the intussusceptum) connecting rectum to the external environment which is not guarded by the sphincters.The assumed mechanism of obstructed defecation is by disruption to the rectum and anal canals ability to contract and fully evacuate rectal contents.
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.