Rectocele or stool quality: what matters more for symptoms of obstructed defecation?

Rectocele is a common condition seen in patients presenting with symptoms of obstructed defecation. We designed a prospective observational study to investigate the relative roles of rectocele and stool quality for such symptoms. Two hundred and forty-two women were assessed in a tertiary urogynaecological unit in a prospective observational study. History taking included questions regarding chronic constipation, incomplete bowel emptying, straining at stool and vaginal digitation, as well as symptoms of prolapse. Stool quality was assessed using the Bristol Stool Form Scale. Rectocele was diagnosed using translabial ultrasound and defined as a diverticulum of the anterior vaginal wall measuring 10 mm or more in depth. The mean age was 53 (17-85) years. Patients reported frequent straining at stool (30%), chronic constipation (20%), vaginal digitation (15%) and incomplete bowel emptying (35%). Median stool quality was 4 (1-7). Ninety-seven women (40%) were found to have a true rectocele on imaging. Vaginal digitation was the only symptom significantly associated with true rectocele. Other symptoms of obstructed defecation were associated with stool quality rather than rectocele. Stool quality was not a confounder of the relationship between true rectocele and symptoms when tested by regression analysis. Stool quality seems to be of greater relevance in the aetiology of symptoms of obstructed defecation than the presence of a rectocele. This was true even when using imaging criteria for a true rectocele rather than just surface anatomy.