Is vaginal flatus related to pelvic floor functional anatomy?

Vaginal flatus is an embarrassing condition that can impair women's quality of life. The underlying pathophysiology is unclear. We aimed to evaluate the association between vaginal flatus and pelvic floor anatomy.

Retrospective observational study on women seen in a tertiary urogynaecological service. All had undergone a standardised interview, clinical examination and four-dimensional transperineal ultrasound. Offline analysis of volume data was performed blinded against clinical data.

Datasets of 570 women were analysed. Five hundred twelve (90%) were vaginally parous. Vaginal flatus was reported by 190 (33%). Mean bother score was 4.2 (SD 3.4, range 0-10). One hundred eighty-five reported frequency of vaginal flatus: it occurred < once a month in 25 (14%), once a month in 70 (38%), once a week in 47 (25%), once daily in 28 (15%) and > once daily in 15 (8%). One hundred two women identified the following precipitating factors: intercourse in 72 (71%), postural change in 22 (22%) and physical activities in 9 (9%). Vaginal birth, central and posterior compartment prolapse, anal incontinence, higher levator resting tone and younger age were associated with vaginal flatus. The latter was moderately correlated with symptom bother (correlation coefficient - 0.21).

Vaginal flatus is a prevalent and bothersome condition affecting one-third of our study population. The condition is associated with pelvic floor functional anatomy. A higher resting tone may confer a higher resistance against which trapped air is expelled during physical activities. Younger age was moderately correlated with symptom bother.