The technical aspects of biofeedback therapy for defecation disorders.

Neuromuscular conditioning using biofeedback techniques is a useful method of treatment for patients with refractory defecation disorders such as fecal incontinence or constipation with obstructive defecation. This article provides current perspectives regarding the principles and techniques of performing biofeedback therapy. In patients with incontinence, the goals are to improve the strength of the anal sphincter, improve sensory perception, and improve coordination between the rectum and anal sphincter. In patients with obstructive defecation, the goals are to relax the anal sphincter, improve rectoanal coordination, and improve sensory perception. Neuromuscular conditioning is an instrument-based learning technique. Over the years, several devices and methods have become available for performing this training, but no single method is either superior or universally popular. The three modalities that are commonly used for neuromuscular conditioning are visual, verbal, and audio feedback. Ideally, the training program should be customized for each patient based on the underlying dysfunction(s). After biofeedback therapy, symptomatic improvement has been reported in 70 to 80% of patients with either incontinence or obstructive defecation. Recent studies also demonstrated objective improvement in anorectal function. In the future, it is likely that simpler and user-friendly, solid-state computerized systems may facilitate a wider use of this treatment.