Biofeedback Therapy in Patients with Functional Evacuation Disorders

Park, Ung Chae

Abstract

Biofeedback therapy has emerged as a useful adjunct for patients with functional evacuation disorders over the past decade. The goals of biofeedback retraining may vary and could depend on the underlying dysfunction. In patients with obstructive defecation, the goals are to relax the anal sphincter, improve rectoanal coordination, and improve sensory perception. Methods of biofeedback therapy varied widely between centers. However, no difference was described when EMG-based biofeedback was compared to manometry-based biofeedback, or when visual or auditory feedback was given. In regards to biofeedback adjuncts, including sensory retraining with either an intrarectal balloon, a portable home-training unit or both can be practicable. There are inconsistencies in the literature regarding the patient selection criteria for biofeedback treatment. The patient group is not homogeneous. Different case selection, different regimens and different methods of biofeedback may explain the variability in success rate. Quality research that would assist in predicting outcome is still lacking. Although no specific denominator could possibly be assigned to correctly predict the overall outcome of therapy, biofeedback is not successful in all patients with outlet obstructed constipation. Results with success rates is ranging from 8.3 percent to 100 percent. The treatment of constipation by biofeedback has been viewed with some skepticism as the low success rate may simply be a placebo effect. The majority of scepticism to therapeutic outcome are derived from entry criteria for treatment. Lower success rates have been described when entry criteria were broadened. Prebiofeedback clinical findings which are presupposed to prognostic relevance are age, gender, duration of symptoms and presence of rectal pain, lower motor neuron disease, and psychiatric problems. I feel strongly that informations about the predictive factors are vital to all physicians either performing or recommending biofeedback to their patients. If biofeedback could be undertaken according to specific criteria, we, colorectal surgeon will save a fruitless endeavour, one would expect more improvements in more patients. Additional well-designed controlled trials are needed to establish the clinical and physiologic factors.