Outcome and management of patients with large rectoanal intussusception.

OBJECTIVES: Rectoanal intussusception is the funnel-shaped infolding of the rectum, which occurs during evacuation. The aims of this study were to evaluate the risk of full thickness rectal prolapse during follow-up of patients with large rectoanal intussusception, and whether therapy improved functional outcome.
METHODS: Between September 1988 and July 1997, patients diagnosed with a large rectoanal intussusception by cinedefecography (intussusception > or = 10 mm, extending into the anal canal) were retrospectively evaluated. Patients with full thickness rectal prolapse on physical examination or cinedefecography were excluded, as were patients with colonic inertia or a history of surgery for rectal prolapse. The patients were divided into three groups according to the treatment received: group I, conservative dietary therapy; group II, biofeedback; and group III, surgery. Outcomes were obtained by postal questionnaires or telephone interviews. Parameters included age, gender, past medical and surgical history, change of bowel habits, fecal incontinence score, and development of full thickness rectal prolapse.
RESULTS: Of the 63 patients, 18 were excluded (seven patients had confirmed full thickness rectal prolapse, four had previous surgery for rectal prolapse, three had colonic inertia, and four died). Follow-up data were obtained in 36 (80%) of the remaining 45 patients. The mean follow-up of this group was 45 months (range, 12-118 months). There were 34 women and two men, with a mean age of 72.4 yr (range, 37-91 yr). The mean size of the intussusception was 2.2 cm (range, 1.0-5.0 cm). The patients were classified as follows: group I, 13 patients (36.1%); group II, 13 patients (36.1%); and group III, 10 patients (27.8%). Subjectively, symptoms improved in five (38.5%), four (30.8%), and six (60.0%) patients in the three groups (p > 0.05). Among the patients with constipation, the decrease in numbers of assisted bowel movements per week (time of diagnosis to present) was significantly greater in group II compared to group 1 (8.1+/-2.8 vs 0.8+/-0.5, respectively, p = 0.004). Among the patients with incontinence, incontinence scores improved more in group II as compared to either group I or group III (time of diagnosis to present, 3.7+/-4.2 to 1.1+/-5.4 vs 1.4+/-2.2, respectively, p > 0.05). Six patients (two in group I, three in group II, and one in group III) had the sensation of rectal prolapse on evacuation; however, only one patient in group I developed full thickness rectal prolapse.
CONCLUSIONS: This study demonstrated that the risk of full thickness rectal prolapse developing in patients medically treated for large intussusception is very small (1/26, 3.8%). Moreover, biofeedback is beneficial to improve the symptoms of both constipation and incontinence in these patients. Therefore, biofeedback should be considered as the initial therapy of choice for large rectoanal intussusception.