Background: A theory of rectal intussusception has been advanced that intrarectal intussusception, intra-anal intussusception, and external rectal prolapse are points on a continuum and are a cause of fecal incontinence and constipation.
Objective: This study evaluates the association among rectal intussusception, constipation, fecal incontinence, and anorectal manometry.
Design: Patients undergoing defecography were studied from a prospectively maintained database and classified according to the Oxford Rectal Prolapse Grade as normal or having intra-rectal, intra-anal, or external intussusception. Patient symptoms were assessed using the Constipation Severity Index and the Fecal Incontinence Severity Index. Quality-of-life surveys were also used. Patients also underwent anorectal manometry.
Settings: The study was conducted at a tertiary care university medical center (Massachusetts General Hospital).
Patients: The study included 147 consecutive patients undergoing evaluation for evacuatory dysfunction and involved defecography, symptoms questionnaires, and anorectal physiology testing from January 2011 to December 2013.
Main outcome measures: Symptom severity and quality-of-life scores were measured, as well as anal manometry results.
Results: Increasing Oxford grade was associated with an increase in severity of fecal incontinence (median score: normal = 23.9, intrarectal = 21.0, intra-anal = 30.0, external prolapse = 35.3; β = 4.71; p = 0.009), which persisted in a multivariable model including age (β = 2.13; p = 0.03), and decreased sphincter pressures (median mean resting pressure: normal = 75.4, intra-rectal = 69.7, intra-anal = 64.3, external prolapse = 48.3; β = -8.57; p = 0.003), which did not persist in a multivariable model. Constipation severity did not increase with rising intussusception (mean score: normal = 37.4, intrarectal = 35.0, intra-anal = 41.4, external prolapse = 32.9; p = 0.79), and balloon expulsion improved rather than worsened (normal = 47.1%, intrarectal = 60.5%, intra-anal = 82.9%, external prolapse = 93.1%; p < 0.001).
Limitations: The study was limited because it was an observational study from a single center.
Conclusions: Increasing grades of rectal intussusception are associated with increasing fecal incontinence but not constipation.