Purpose: Rectal intussusception is a common finding at evacuation proctography; however, its significance has been debated. This study was designed to characterize clinically and physiologically a large group of patients with rectal intussusception and test the hypothesis that certain symptoms are predictive of this finding on evacuation proctography.
Methods: A total of 896 patients underwent evacuation proctography from which three groups were identified: those with isolated rectal intussusception (n = 125), those with isolated rectocele (n = 100), and those with both abnormalities (n = 152). Multivariate analyses were used to identify symptoms predictive of findings by evacuation proctography.
Results: The symptoms of anorectal pain and prolapse were highly predictive of the finding of isolated intussusception over rectocele (odds ratio, 3.6, P = 0.006; odds ratio, 4.9, P < 0.001) or combined intussusception and rectocele (odds ratio, 2.9, P = 0.02; odds ratio, 2.4, P = 0.03). The symptom of "toilet revisiting" was associated with the finding of rectoanal intussusception (odds ratio, 3.55, P = 0.04). Although patients with mechanically obstructing intussuscepta evacuated slower and less completely (P < 0.001) than those with nonobstructing intussuscepta, no symptom was predictive of this finding on evacuation proctography.
Conclusions: Although certain symptoms are predictive of the finding of rectal intussusception, there is a wide overlap with symptoms of rectocele, another common cause of evacuatory dysfunction. Furthermore, the observation that "obstruction to evacuation" made on proctography had no impact on the incidence of evacuatory symptoms suggests that beyond simply demonstrating the presence of an intussusception, analysis of proctography and subclassifying intussusception morphology seems of little clinical significance, and selection for surgical intervention on the basis of proctographic findings may be illogical.