Efficacy of antibiotherapy for treating flatus incontinence associated with small intestinal bacterial overgrowth: A pilot randomized trial

PLoS One. 2017 Aug 1;12(8):e0180835. doi: 10.1371/journal.pone.0180835. eCollection 2017.


Aim: 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.

Methods: 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.

Results: 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).

Conclusion: 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.

Publication types

  • Clinical Trial, Phase II
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Anti-Bacterial Agents / therapeutic use*
  • Bacterial Infections / drug therapy*
  • Breath Tests
  • Charcoal / chemistry
  • Drug Administration Schedule
  • Fecal Incontinence / drug therapy*
  • Fecal Incontinence / microbiology
  • Female
  • Flatulence / drug therapy*
  • Flatulence / microbiology
  • Gases
  • Gastrointestinal Microbiome
  • Glucose / analysis
  • Humans
  • Intestine, Small / microbiology
  • Intestine, Small / physiopathology
  • Male
  • Metronidazole / therapeutic use*
  • Middle Aged
  • Odds Ratio
  • Pilot Projects
  • Prospective Studies
  • Quality of Life
  • Simethicone / therapeutic use
  • Treatment Outcome


  • Anti-Bacterial Agents
  • Gases
  • Metronidazole
  • Charcoal
  • Simethicone
  • Glucose

Grant support

This work was funded in part by the French Ministry of Health and the French National Society of Gastroenterology (SNFGE) and the French Ministry of Health Haute-Normandie Region in the framework of the Program of Clinical Research call for projects, Rouen University Hospital (N° 2008/073HP). The funders had no role in study design data, data collection and analysis, decision to publish, or preparation of the manuscript.