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.
Elderly, or other medically high-risk patients are usually treated by perineal procedures,  as they can be performed under a regional anesthetic, or even local anesthetic with intravenous sedation, thus avoid the risks of a general anesthetic. Alternatively, perineal procedures may be selected to reduce risk of nerve damage, for example in young male patients for whom sexual dysfunction may be a major concern.Perineal rectosigmoidectomy
The goal of Perineal rectosigmoidectomy is to resect or remove the redundant bowel. This is done through the perineum. The lower rectum is anchored to the sacrum through fibrosis in order to prevent future prolapse. The full thickness of the rectal wall is incised at a level just above the dentate line. Redundant rectal and sigmoid wall is removed and the new edge of colon is reconnected (anastomosed) with the anal canal with stitches or staples. This procedure may be combined with levatorplasty, to tighten the pelvic muscles. A combined a perineal proctosigmoidectomy with anterior levatorplasty is also called an Altemeier procedure. Levatorplasty is performed to correct levator diastasis which is commonly associated with rectal prolapse. Perineal rectosigmoidectomy was first introduced by Mikulicz in 1899, and it remained the preferred treatment in Europe for many years. It was Popularized by Altemeier. The procedure is simple, safe and effective. Continence levatorplasty may enhance restoration of continence (2/3 of patients). Complications occur in less than 10% of cases, and include pelvic bleeding, pelvic abscess and anastomotic dehiscence (splitting apart of the stitches inside), bleeding or leak at a dehiscence Mortality is low.