Randomized controlled trial of topical phenylephrine in the treatment of faecal incontinence

Background: Anal incontinence due to internal sphincter dysfunction is not amenable to simple surgical repair. The alpha-adrenergic agonist phenylephr ine produces contraction of the internal sphincter and raises resting press ure when applied topically in healthy volunteers. The effect of topical phe nylephrine in the treatment of faecal incontinence due to internal sphincte r dysfunction was investigated. Methods: Thirty-six patients (22 women) aged 28-81 (mean 58) years with fae cal incontinence and ultrasonographically structurally normal anal sphincte r muscles were treated with topical 10 per cent phenylephrine and placebo g els, allocated in random order in a double-blind crossover study. Maximum r esting anal sphincter pressure and anodermal blood flow were measured. A sy mptom questionnaire was completed and incontinence score determined using a validated scale. Results: There were no significant differences in incontinence score, resti ng anal pressure and anodermal blood flow between the active and placebo tr eatments. Six patients on active treatment and two on placebo experienced m ore than 75 per cent subjective improvement. Three patients developed aller gic dermatitis to phenylephrine. Conclusion: This is the first study of the use of a topical pharmacological agent to treat faecal incontinence. This concentration of topical phenylep hrine did not produce a significant improvement in symptoms or function. A subgroup of patients may respond. Further studies are required with increas ed concentrations.