Flatus Incontinence and Fecal Incontinence: A Case-Control Study

BACKGROUND: Incontinence to gas can be a troublesome symptom impacting quality of life for patients even in the absence of fecal incontinence. Whether isolated flatus incontinence represents part of the spectrum of true fecal incontinence or a separate condition with a different pathophysiology remains unclear.OBJECTIVE: This study aimed to evaluate the clinical features and anorectal physiology in women presenting with severe isolated flatus incontinence compared to women with fecal incontinence and healthy asymptomatic women.DESIGN: This was a retrospective case-control study of prospectively collected data.SETTINGS: Data from participants were obtained from a single tertiary Neurogastroenterology Unit in Sydney, Australia.PATIENTS: Data from 34 patients with severe isolated flatus incontinence, 127 women with fecal incontinence, and 44 healthy women were analyzed.MAIN OUTCOME MEASURES: The primary outcomes were clinical (including demographic, obstetric, and symptom variables) and physiological differences across the 3 groups.RESULTS: Patients with flatus incontinence were significantly younger (mean 39 versus 63 years; p = 0.0001), had a shorter history of experiencing their symptoms (p = 0.0001), and had harder stool form than patients with fecal incontinence (p = 0.02). Those with flatus incontinence had an adverse obstetric history and impaired anorectal physiology (motor and sensory, specifically rectal hypersensitivity) but to a lesser extent than patients with fecal incontinence.LIMITATIONS: This study was limited by its retrospective design and modest sample size.CONCLUSIONS: Anorectal physiology was impaired in patients with flatus incontinence compared to healthy controls, but to a lesser extent than in those with fecal incontinence, raising the possibility that flatus incontinence could be a precursor to fecal incontinence. As clinical and physiological findings are different from healthy controls (including the presence of visceral hypersensitivity), isolated flatus incontinence should be considered a distinct clinical entity (like other functional GI disorders), or possibly part of an incontinence spectrum rather than purely a normal phenomenon.

Automated summary

This study found that women with isolated flatus incontinence have different clinical and physiological characteristics compared to healthy women and women with fecal incontinence. It suggests that flatus incontinence may be a precursor or part of the spectrum of fecal incontinence, rather than just a normal phenomenon.