Background: Rectal intussusception may be the initial abnormality of a progressive pelvic floor disorder culminating in external prolapse. The evidence, however, is unclear, and the pathophysiological mechanisms underlying this condition are unknown.
Objective: The aim of this study is to identify the relationship between age, symptom duration, anorectal physiology parameters, and type of intussusception/prolapse in order to appreciate the natural history of the condition.
Design: All female patients diagnosed proctographically with rectorectal/rectoanal intussusception or external prolapse between 1994 and 2007 were studied. Demographics, symptom duration, and anorectal physiology results were compared between these proctographic groups. Patients with repeat proctographic evaluation were also analyzed separately.
Settings: This investigation was conducted at a tertiary academic colorectal center.
Patients: A total of 1014 women (median age, 51; range, 16-96), including 32 who underwent repeat proctography, were analyzed.
Main outcome measures: The primary outcomes measured were the differences in median age, symptom duration, and anorectal physiology parameters between the proctographic groups.
Results: The cohort exhibited a statistically significant difference (p = 0.0001) in the median age of the proctographic groups with older patients diagnosed with rectoanal rather than rectorectal intussusception, which was supported by uni- and multivariate modeling. Symptom duration was statistically different (p = 0.0002) between the rectorectal intussusception (60 months; range, 1-936) and external rectal prolapse patient groups (36 months; range, 2-732). Patients with external rectal prolapse had statistically lower anal resting (median, 41 versus 77 cmH2O) and squeeze pressures (median 40 versus 56 cmH2O) than patients with rectorectal intussusception. Within 2 years, 19.2% and 3.8% of patients with rectorectal intussusception on the initial proctogram demonstrated progression to rectoanal intussusception and external prolapse.
Limitations: This study was limited by its retrospective nature.
Conclusion: Rectal intussusception may be an initial abnormality leading to external prolapse, but this appears to happen infrequently. Long-term observational studies are required to fully understand its natural history.