Effects of clonidine in women with fecal incontinence.

Background & Aims: Some women with urge-predominant fecal incontinence (FI) have diarrhea-predominant irritable bowel syndrome and a stiffer and hypersensitive rectum. We evaluated the effects of the α2-adrenergic agonist clonidine on symptoms and anorectal functions in women with FI in a prospective, placebo-controlled trial.

Methods: We assessed bowel symptoms and anorectal functions (anal pressures, rectal compliance, and sensation) in 43 women (age, 58 ± 2 y) with urge-predominant FI, randomly assigned to groups given oral clonidine (0.1 mg, twice daily) or placebo for 4 weeks. Before and after administration of the medication, anal pressures were evaluated by manometry, and rectal compliance and sensation were measured using a barostat. Anal sphincter injury was evaluated by endoanal magnetic resonance imaging. Bowel symptoms were recorded in daily and weekly diaries. The primary end point was the FI and Constipation Assessment symptom severity score.

Results: FI scores decreased from 9.1 ± 0.3 to 7.6 ± 0.5 among subjects given placebo and from 8.1 ± 0.4 to 6.5 ± 0.6 among patients given clonidine. Clonidine did not affect FI symptom severity, bowel symptoms (stool consistency or frequency), anal pressures, rectal compliance, or sensation compared with placebo. However, when baseline data were used to categorize subjects as those with or without diarrhea, clonidine reduced the proportion of loose stools in patients with diarrhea only (P = .018). Clonidine also reduced the proportion of days with FI in patients with diarrhea (P = .0825).

Conclusions: Overall, clonidine did not affect bowel symptoms, fecal continence, or anorectal functions, compared with placebo, in women with urge-predominant FI. Among patients with diarrhea, clonidine increased stool consistency, with a borderline significant improvement in fecal continence. ClinicalTrials.gov, Number NCT00884832.