Biofeedback treatment of fecal incontinence - A critical review

PURPOSE. The aims of this review are 1) to critically evaluate the literatu re on the efficacy of biofeedback treatment for fecal incontinence, 2) to c ompare different types of biofeedback, and 3) to identify patient character istics which predict a successful outcome. METHODS: The MEDLINE database wa s searched for articles published between 1973 and 1999 which included the terms "biofeedback" and "fecal incontinence." Pediatric and adult articles in any language were screened. Inclusion for review required that the study be prospective, have Eve or more subjects, and have a description of the t reatment protocol. RESULTS: Thirty-five studies were reviewed. Only six stu dies used a parallel treatment design and just three of those randomized su bjects to treatment groups. A meta-analysis (weighted by subjects) was perf ormed to compare the results of two treatment protocols that dominate the l iterature. The mean success rate of studies using Coordination training (i. e., coordinating pelvic floor muscle contraction with the sensation of rect al filling) was 67 percent, while the mean success rate for studies using S trength training (ie., pelvic floor muscle contraction) was 70 percent. Fur thermore, the mean success rate for those Strength training studies using e lectromyographic biofeedback was 74 percent, while the mean success rate fo r studies using anal canal pressure biofeedback Strength training was 64 pe rcent. However, these conclusions are limited by the absence of clearly ide ntified criteria for determining success. There are also inconsistencies in the literature regarding the patient selection criteria, severity and caus e of symptoms, amount of treatment, as well as the type of biofeedback prot ocols and instrumentation used. Finally, no patient characteristics were id entified that would assist in predicting successful outcome. CONCLUSION: Al though most studies report positive results using biofeedback to treat feta l incontinence, quality research is lacking. Recommendations are made for f uture investigations to 1) improve experimental design, 2) include long ter m follow-up data: and 3) to use an adequate sample size that allows for mea ningful analysis.