Biofeedback is a form of treatment that has no adverse effects and can be provided by physician extenders. The therapy relies on patients' ability to learn how to influence their bodily functions through dedicated machinery and teaching. This Review provides a comprehensive overview of all potential therapeutic applications of biofeedback for functional constipation, fecal incontinence, functional anorectal pain, IBS, functional dyspepsia, and aerophagia. Practical clinical applications of biofeedback therapy supported by randomized, controlled trials (RCTs) are limited to fecal incontinence and dyssynergic defecation. For fecal incontinence, RCTs suggest that biofeedback combining strength training and sensory discrimination training is effective in approximately 75% of patients and is more effective than placebo. However, verbal feedback provided by a therapist during extended digital examination may be equally effective, and children whose fecal incontinence is associated with constipation plus fecal impaction do no better with biofeedback than medical management. For dyssynergic defecation, RCTs show that biofeedback combining pelvic floor muscle relaxation training, practice in defecating a water-filled balloon, and instruction in effective straining is effective in approximately 70% of patients who have failed to respond to laxative treatment. For both incontinence and dyssynergic defecation, the benefits of biofeedback last at least 12 months.