Rectal prolapse: Pathophysiology

Abstract

Rectal prolapse, procidentia, complete prolapse or first-degree prolapse, is defined as a circumferential, full-thickness intussusception of the rectal wall with protrusion beyond the anal canal [1]. This definition emphasises two important points: (1) rectal prolapse is the expression of a fullthickness intussusception, and (2) protrusion is outside the anus. The cause of rectal prolapse is still not completely understood. It is likely the result of a multifactorial aetiology, and any single standard theory would be improbable and imprecise. This implies that each patient potentially has his or her own specific pathogenetic profile, which is the result of a mix of several aetiological factors. A great division has developed between supporters of the sliding hernia and those who support the rectal intussusception theory. Rectal prolapse has been related to either a form of sliding hernia, as most patients have a redundant sigmoid colon, deep pelvic-peritoneal cul-de-sac, diastasis of the levator ani muscles, loss of posterior rectal fixation and loss of the usual anorectal angle; or to the final stages of a progressively worsening intussusception, as similarities in manometric findings can be found among patients with rectal prolapse, rectoanal intussusception and solitary rectal ulcer syndrome. © 2008 Springer-Verlag Italia.