Outcome and predictors of success of biofeedback for constipation.

BACKGROUND: A study was undertaken to determine outcome and to identify predictors of success for biofeedback for constipation.
METHODS: Patients who had at least one biofeedback session were evaluated whether or not they completed a treatment course. Parameters assessed included use of cathartics, number of spontaneous bowel movements per week, presence of rectal pain, number of biofeedback sessions and results of anorectal physiology.
RESULTS: A total of 194 patients (59 male, 135 female) of median age 71 (range 11-96) years, including 30 with concomitant rectal pain, were treated. The median number of spontaneous bowel movements per week before treatment was 0. Some 35 per cent of patients had complete success (three or more spontaneous bowel movements per week with discontinuation of cathartics), 13 per cent had partial success (fewer than three spontaneous bowel movements per week with continued use of cathartics) and 51 per cent had no improvement. Neither patient age, sex nor duration of symptoms significantly affected outcome. Only 18 per cent of patients who had between two and four sessions had complete success, compared with 44 per cent of those who had five or more (P < 0.001). A total of 63 per cent of patients who completed the treatment protocol experienced complete success, compared with 25 per cent of those who self-discharged (P < 0.0001).
CONCLUSIONS: This large study indicates that the success rate of biofeedback for patients with constipation is less than previously reported. However, the success rate improves significantly after five or more sessions and is significantly related to the patient's willingness to complete treatment.