Balloon expulsion testing for the diagnosis of dyssynergic defecation in women with chronic constipation

Dyssynergic defecation can be difficult to diagnose. Anorectal manometry and defecography are often used to make this diagnosis. However, these tests are expensive and require expertise. Balloon expulsion testing may be a simple alternative. We compared balloon expulsion to anorectal manometry and defecography for diagnosing dyssynergia in women with chronic constipation.

We conducted a retrospective review. All women presenting for evaluation of chronic constipation who underwent concurrent balloon testing, manometry, and defecography were included. A diagnosis of dyssynergic defecation was established by either defecography revealing prolonged/incomplete rectal evacuation and/or by manometry revealing paradoxical contraction/inadequate relaxation of the pelvic floor. Inability to expel a 50-ml balloon defined dyssynergic defecation by balloon testing. Sensitivity, specificity, and predictive values were calculated.

A total of 61 women met inclusion criteria. Mean age was 50 years. There were 36 women (59 %) who met Rome III criteria for dyssynergic defecation on defecography and/or manometry. Only 12 of these 36 (33 %) were similarly diagnosed by balloon testing. The sensitivity and positive predictive value of balloon testing for dyssynergia were 33 and 71 %, respectively. Of the 25 (41 %) women who did not meet Rome III criteria for dyssynergia on defecography and/or manometry, 20 (80 %) also had negative balloon testing. Thus, the specificity and negative predictive value of balloon testing for diagnosing dyssynergia were 80 and 50 %, respectively.

In our population, balloon expulsion was not an ideal screening test for dyssynergic defecation in women with constipation. Multimodal testing is necessary for more accurate diagnosis.