BACKGROUND: Constipation is highly prevalent. Women with constipation are evaluated for the presence of vaginal prolapse that may contribute to obstructed defecation syndrome. Defecography can identify anatomic causes of obstructed defecation syndrome (rectocele, intussusception, and enterocele). OBJECTIVE:This study aimed to assess the characteristics of women with obstructed defecation syndrome and radiographic rectoceles with and without posterior vaginal wall prolapse and to characterize the relationship between anatomical abnormalities and dysfunction.DESIGN: This is a retrospective case-control study of women with obstructed defecation syndrome who had radiographic rectoceles on defecography. SETTINGS:Women who presented to a Pelvic Floor Disorders Center were included.PATIENTS: Cases were defined as constipated women with radiographic rectoceles and at least stage II posterior vaginal wall prolapse on examination. Controls were patients with radiographic rectoceles but without posterior vaginal wall prolapse on examination. MAIN OUTCOME MEASURES:Patient characteristics, anorectal testing results, and validated questionnaires were compared between groups. RESULTS:A total of 106 women met inclusion criteria. Women with posterior vaginal wall prolapse (48 (45.3%)) had larger rectoceles on defecography than women without it on examination (3.4 cm vs 3.0 cm, p < 0.01). Women with posterior vaginal wall prolapse on examination were more likely to splint during defecation than women without vaginal wall prolapse (63.8% vs 27.3%, p < 0.01). All other defecatory symptoms, anorectal manometry parameters, and questionnaire responses were similar between groups. LIMITATIONS:This study was limited by its retrospective study design. Our data were taken from a single institution within a center specializing in the treatment of pelvic floor disorders, potentially limiting generalizability.CONCLUSIONS: Patients with constipation, radiographic rectoceles, and vaginal prolapse may differ from those without evidence of prolapse. Patients with vaginal prolapse were more likely to splint to aide evacuation and demonstrated larger rectoceles on defecography. Further studies are needed to determine whether constipation Funding/Support: None reported.