Date Published: August 1, 2017
Publisher: Public Library of Science
Author(s): Chloé Melchior, Guillaume Gourcerol, Valérie Bridoux, Philippe Ducrotté, Jean-François Quinton, Anne-Marie Leroi, Jan P. A. Baak.
An increase in intestinal gas production due to small intestinal bowel overgrowth (SIBO) is a contributing factor for flatus incontinence. The aims of our study were to assess the efficacy of metronidazole in a select population of patients with flatus incontinence associated with SIBO and to compare its efficacy with that of a combination of simethicone and activated charcoal (SC; Carbosylane) in randomized experimental arms.
Adult patients suffering from flatus incontinence associated with SIBO diagnosed by a glucose breath test were enrolled in the study. They were given metronidazole or Carbosylane (SC) for 10 days. The reduction in the mean daily number of gas leakages reported in a 3-day diary before and at the end of the treatment was used as the primary endpoint.
Of 52 consecutive subjects with flatus incontinence, 23 (44%) had SIBO, 16 (33%) of whom were included in and completed the study. The relative reduction in flatus incontinence episodes was significantly higher in the metronidazole than in the SC group (66.8±34.8% vs. 25±50%, P = 0.03), decreasing by more than 50% in 7 (87.5%) of the subjects in the metronidazole group compared with only 1 (12.5%) in the SC group (odds ratio 1.9, 95% confidence interval 0.9–56.9, P = 0.06).
Our results show a promising trend indicating that metronidazole might significantly improve flatus incontinence associated with SIBO and might be more successful in treating flatus incontinence than gas absorbents.
In most patients, involuntary leakage of gas through the anus is limited to flatus incontinence, although this type of incontinence is occasionally associated with liquid or solid stool incontinence. Flatus incontinence is the most common type of anal incontinence, with a prevalence estimated at approximately 33% of the general adult population . While it appears to have less impact upon quality of life than fecal incontinence , it remains an embarrassing and socially restricting problem [3–4] due to the poor efficacy of the therapeutic options, which are mainly restricted to gas absorbents. Although the mechanism of flatus incontinence is poorly understood, increased intestinal gas production is likely involved.
The results of the pilot controlled phase II study reported here showed that metronidazole given three times a day for 10 days significantly reduces flatus incontinence episodes in patients in whom the incontinence is associated with SIBO. The relative reduction in flatus incontinence episodes was 67% with the metronidazole treatment, which was significantly higher than with the SC treatment (25%). The percentage of improvement for patients in the metronidazole group was close to statistical significance. Several studies have previously shown that antibiotics are more effective than placebos in eradicating SIBO and that the eradication may be correlated with a clinical response16-18. However, these studies evaluated diarrhea, abdominal pain or discomfort, bloating, flatulence, nausea, constipation, tenesmus, and weight loss [16–18]. To our knowledge, the present study is the first to suggest that antibiotherapy might be more successful in treating flatus incontinence associated with SIBO than gas absorbents.
Our results show a promising trend indicating that metronidazole might significantly improve flatus incontinence associated with SIBO. A multicenter prospective randomized trial with a large patient cohort will be required to definitively prove whether metronidazole is more successful in treating flatus incontinence than gas absorbents. Although further studies are needed to determine the best antibiotic to use and the optimal duration of the treatment, periodic administration of antibiotics might serve as a possible therapeutic approach for the treatment of flatus incontinence associated with SIBO. Lastly, glucose breath tests may be helpful in diagnosing SIBO and monitoring the effectiveness of antibiotherapies in individual patients.