of the perineum during defecation, urgency, frequency or intermittent fecal incontinence. it has been observed that intussusceptions of thickness ≥3 mm, and those that appear to cause obstruction to rectal evacuation may give clinical symptoms. cause there are two schools of thought regarding the nature of internal intussusception, viz: whether it is a primary phenomenon, or secondary to (a consequence of) another condition. some believe that it represents the initial form of a progressive spectrum of disorders the extreme of which is external rectal prolapse. the intermediary stages would be gradually increasing sizes of intussusception. the folding section of rectum can cause repeated trauma to the mucosa, and can cause solitary rectal ulcer syndrome. however, internal intussusception rarely progress to external rectal prolapse. others argue that the majority of patients appear to have rectal intussusception as a consequence of obstructed defecation rather than a cause, possibly related to excessive straining in patients with obstructed defecation. patients with other causes of obstructed defecation (outlet obstruction) like anismus also tend to have higher incidence of internal intussusception. enteroceles are coexistent in 11% of patients with internal intussusception. symptoms of internal intussusception overlap with those of rectocele, indeed the 2 conditions can occur together. patients with solitary rectal ulcer syndrome combined with internal intussusception (as 94% of srus patients have) were shown to have altered rectal wall biomechanics compared to patients with internal intussusception alone. the presumed mechanism of the obstructed defecation is by telescoping of the intussusceptum, occluding the rectal lumen during attempted defecation. one study analysed resected rectal wall specimens in patients with obstructed defecation associated with rectal intussusception undergoing stapled trans-anal rectal resection. they reported abnormalities of the enteric nervous system and estrogen receptors. one study concluded that intussusception of the anterior rectal wall shares the same cause as rectocele, namely deficient recto-vaginal ligamentous support. comorbidities and complications the following conditions occur more commonly in patients with internal rectal intussusception than in the general population: rectocele solitary rectal ulcer syndrome. diagnosis unlike external rectal prolapse, internal rectal intussusception is not visible externally, but it may still be diagnosed by digital rectal examination, while the patient strains as if to defecate. imaging such as a defecating proctogram or dynamic mri defecography can demonstrate the abnormal folding of the rectal wall. some have advocated the use of anorectal physiology testing (anorectal manometry). treatment non surgical measures to treat internal intussusception include pelvic floor retraining, a bulking agent (e.g. psyllium), suppositories or enemas to relieve constipation and straining. if there is incontinence (fecal leakage or more severe fi), or paradoxical contraction of the pelvic floor (anismus), then biofeedback retraining is indicated. some researchers advise that internal intussusception be managed conservatively, compared to external rectal prolapse which usually requires surgery. as with external rectal prolapse, there are a great many different surgical interventions described. generally, a section of rectal wall can be resected (removed), or the rectum can be fixed (rectopexy) to its original position against the sacral vertebrae, or a combination of both methods. surgery for internal rectal prolapse can be via the abdominal approach or the transanal approach. it is clear that there is a wide spectrum of symptom severity, meaning that some patients may benefit from surgery and others may not. many procedures receive conflicting reports of success, leading to a lack of any consensus about the best way to manage this problem. relapse of the intussusception after treatment is a problem. two of the most commonly employed procedures are discussed below. laparoscopic ventral (mesh) rectopexy (lvr) this procedure aims to " the descent of the posterior and middle pelvic compartments combined with reinforcement of the rectovaginal septum". rectopexy has been shown to improve anal incontinence (fecal leakage) in patients with rectal intussusception. the operation has been shown to have low recurrence rate (around 5%). it also improves obstructed defecation symptoms. complications include constipation, which is reduced if the technique does not use posterior rectal mobilization (freeing the rectum from its attached back surface). the advantage of the laparoscopic approach is decreased healing time and less complications. stapled trans-anal rectal resection (starr) this operation aims to "remove the anorectal mucosa circumferential and reinforce the anterior anorectal junction wall with the use of a circular stapler". in contrast to other methods, starr does not correct the descent of the rectum, it removes the redundant tissue. the technique was developed from a similar stapling procedure for prolapsing hemorrhoids. since, specialized circular staplers have been developed for use in external rectal prolapse and internal rectal intussusception. complications, sometimes serious, have been reported following starr, but the procedure is now considered safe and effective. starr is contraindicated in patients with weak sphincters (fecal incontinence and urgency are a possible complication) and with anismus (paradoxical contraction of the pelvic floor during attempted defecation). the operation has been shown to improve rectal sensitivity and decrease rectal volume, the reason thought to create urgency. 90% of patients do not report urgency 12 months after the operation. the anal sphincter may also be stretched during the operation. starr was compared with biofeedback and found to be more effective at reducing symptoms and improving quality of life. mucosal prolapse rectal mucosal prolapse (mucosal prolapse, anal mucosal prolapse) is a sub-type of rectal prolapse, and refers to abnormal descent of the rectal mucosa through the anus. it is different to an internal intussusception (occult prolapse) or a complete rectal prolapse (external prolapse, procidentia) because these conditions involve the full thickness of the rectal wall, rather than only the mucosa (lining). mucosal prolapse is a different condition to prolapsing (3rd or 4th degree) hemorrhoids, although they may look similar. rectal mucosal prolapse can be a cause of obstructed defecation (outlet obstruction). and rectal malodor. symptoms symptom severity increases with the size of the prolapse, and whether it spontaneously reduces after defecation, requires manual reduction by the patient, or becomes irreducible. the symptoms are identical to advanced hemorrhoidal disease, and include: fecal leakage causing staining of undergarments rectal bleeding mucous rectal discharge rectal pain pruritus ani cause the condition, along with complete rectal prolapse and internal rectal intussusception, is thought to be related to chronic straining during defecation and constipation. mucosal prolapse occurs when the results from loosening of the submucosal attachments (between the mucosal layer and the muscularis propria) of the distal rectum. the section of prolapsed rectal mucosa can become ulcerated, leading to bleeding. diagnosis mucosal prolapse can be differentiated from a full thickness external rectal prolapse (a complete rectal prolapse) by the orientation of the folds (furrows) in the prolapsed section. in full thickness rectal prolapse, these folds run circumferential. in mucosal prolapse, these folds are radially. the folds in mucosal prolapse are usually associated with internal hemorrhoids. treatment eua (examination under anesthesia) of anorectum and banding of the mucosa with rubber bands. solitary rectal ulcer syndrome and colitis cystica profunda solitary rectal ulcer syndrome (srus, sru), is a disorder of the rectum and anal canal, caused by straining and increased pressure during defecation. this increased pressure causes the anterior portion of the rectal lining to be forced into the anal canal (an internal rectal intussusception). the lining of the rectum is repeatedly damaged by this friction, resulting in ulceration. srus can therefore be considered to be a consequence of internal intussusception (a sub type of rectal prolapse), which can be demonstrated in 94% of cases. it may be asymptomatic, but it can cause rectal pain, rectal bleeding, rectal malodor, incomplete evacuation and obstructed defecation (rectal outlet obstruction). symptoms symptoms include: straining during defecation mucous rectal discharge rectal bleeding sensation of incomplete evacuation (tenesmus) constipation, or more rarely diarrhea fecal incontinence (rarely) prevalence the condition is thought to be uncommon. it usually occurs in young adults, but children can be affected too. cause the essential cause of srus is thought to be related to too much straining during defecation. overactivity of the anal sphincter during defecation causes the patient to require more effort to expel stool. this pressure is produced by the modified valsalva manovoure (attempted forced exhalation against a closed glottis, resulting in increased abdominal and intra-rectal pressure). patiest with srus were shown to have higher intra-rectal pressures when straining than healthy controls. srus is also associated with prolonged and incomplete evacuation of stool. more effort is required because of concomitant anismus, or non-relaxation/paradoxical contraction of puborectalis (which should normally relax during defecation). the increased pressure forces the anterior rectal lining against the contracted puborectalis and frequently the lining prolapses into the anal canal during straining and then returns to its normal position afterwards. the repeated trapping of the lining can cause the tissue to become swollen and congested. ulceration is thought to be caused by resulting poor blood supply (ischemia), combined with repeated frictional trauma from the prolapsing lining, and exposure to increased pressure are thought to cause ulceration. trauma from hard stools may also contribute. the site of the ulcer is typically on the anterior wall of the rectal ampulla, about 7–10 cm from the anus. however, the area may of ulceration may be closer to the anus, deeper inside, or on the lateral or posterior rectal walls. the name "solitary" can be misleading since there may be more than one ulcer present. furthermore, there is a "preulcerative phase" where there is no ulcer at all. pathological specimens of sections of rectal wall taken from srus patients show thickening and replacement of muscle with fibrous tissue and excess collagen. rarely, srus can present as polyps in the rectum. srus is therefore associated and with internal, and more rarely, external rectal prolapse. some believe that srus represents a spectrum of different diseases with different causes. another condition associated with internal intussusception is colitis cystica profunda (also known as ccp, or proctitis cystica profunda), which is cystica profunda in the rectum. 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 adenocarcinoma defecography, 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. polyethylene glycol, and biofeedback retraining to coordinate pelvic floor during defecation. surgery may be considered, but only if non surgical treatment has failed and the symptoms are severe enough to warrant the intervention. improvement with surgery is about 55-60%. ulceration may persist even when symptoms resolve. mucosal prolapse syndrome a group of conditions known as mucosal prolapse syndrome (mps) has now been recognized. it includes srus, rectal prolapse, proctitis cystica profunda, and inflammatory polyps. it is classified as a chronic benign inflammatory disorder. the unifying feature is varying degrees of rectal prolapse, whether internal intussusception (occult prolapse) or external prolapse. epidemiology rectal prolapse affects less than 0.5% of the general population. it affects women more commonly, with a female to male ratio of 9:1. pornography rosebud pornography and prolapse pornography (or rosebudding or rectal prolapse pornography) is an anal sex practice that occurs in some extreme anal pornography wherein a pornographic actor or actress performs