Symptoms
Internal intussusception may be asymptomatic, but common symptoms include:
Fecal leakage
Sensation of obstructed defecation (tenesmus). Pelvic pain. Rectal bleeding.Recto-rectal intussusceptions may be asymptomatic, apart from mild obstructed defecation. "interrupted defaecation" in the morning is thought by some to be characteristic.Recto-anal intussusceptions commonly give more severe symptoms of straining, incomplete evacuation, need for digital evacuation of stool, need for support 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.
It is usually not necessary with obvious external rectal prolapse. Defecography may demonstrate associated conditions like cystocele, vaginal vault prolapse or enterocele. Colonic transit studies
Colonic transit studies may be used to rule out colonic inertia if there is a history of severe constipation. Continent prolapse patients with slow transit constipation, and who are fit for surgery may benefit from subtotal colectomy with rectopexy. Anorectal manometry
This investigation objectively documents the functional status of the sphincters. However, the clinical significance of the findings are disputed by some. It may be used to assess for pelvic floor dyssenergia, (anismus is a contraindication for certain surgeries, e.g. STARR), and these patients may benefit from post-operative biofeedback therapy. Decreased squeeze and resting pressures are usually the findings, and this may predate the development of the prolapse. Resting tone is usually preserved in patients with mucosal prolapse. In patients with reduced resting pressure, levatorplasty may be combined with prolapse repair to further improve continence. Anal electromyography/pudendal nerve testing
It may be used to evaluate incontinence, but there is disagreement about what relevance the results may show, as rarely do they mandate a change of surgical plan. There may be denervation of striated musculature on the electromyogram. Increased nerve conduction periods (nerve damage), this may be significant in predicting post-operative incontinence. Complete rectal prolapse
Rectal prolapse is a "falling down" of the rectum so that it is visible externally. The appearance is of a reddened, proboscis-like object through the anal sphincters. Patients find the condition embarrassing.