Defecation disorders are mainly constipation and anal incontinence. Since Birk reported biofeedback therapy in 1973 and proposed the concept of “behavioral medicine”, this therapy has been gradually applied to the treatment of many physical and mental diseases. Because of its non-invasive, non-side effects, repeated treatment and other advantages, it is the first-line treatment method for bowel disorders. 1, the concept of biofeedback training Biofeedback training is the use of biofeedback instrument, people are not easily perceived physiological signals amplified and displayed, so that the subject through learning and repeated practice, familiar with and master this physiological changes, the formation and maintenance of specific parts of the body self-control ability to improve function. This can be done by collecting EMG, EEG, skin temperature, skin electricity, blood pressure, heart rate, and amplifying them into visible graphs and audible sounds to help the subject cognitively mobilize “subjective initiative” and consciously control the body. Biofeedback training is a process of continuous learning, “knowing oneself” and “changing oneself”. For the treatment of defecation disorders mainly through electromyography-mediated or pressure-mediated biofeedback to achieve, the subject intuitively perceives the functional state of the pelvic floor muscles during defecation, and learns how to appropriately relax and contract the pelvic floor muscles. 2.The development of biofeedback therapy instrument can be roughly divided into three stages according to the development of the processing method of the collected signal. In the first stage, the signal is collected by the Perryanal endoanal surface electromyography probe, then amplified and filtered, and transformed into digital signal, and then the curve is traced on the screen and the “bla bla” sound of muscle contraction is heard. The main drawbacks of this phase are signal distortion, difficulty in patient understanding, and lack of training programs, which affect the efficacy of the treatment due to poor patient compliance. The authors treated 3O patients with pelvic floor dystonia syndrome using this stage of instrumentation, and 30% of them showed significant symptom relief after treatment. The second stage of development mainly optimized the hardware based on the first stage and processed the boring and difficult signal recording into a humanized animation form, so that patients could have a better knowledge of their abnormal signals through the therapist’s explanation and could better human-computer interaction, even for the training of children with defecation disorders. In the third stage, with the in-depth research on pelvic floor physiology, targeted training programs were emphasized and triggered electrical stimulation biofeedback technology was used to develop the pelvic biofeedback electrical stimulation therapy instrument. Domestic Sun Daqing et al. used the method to treat 36 cases of pediatric defecation disorders, with an efficiency of 72.7% to 82.4%, and the second stage of the device control that feedback therapy combined with electrical stimulation, especially for lowering the rectal sensory threshold more effective, the emergence rate of anal canal contraction reflex in children with fecal incontinence rose from 30.6% before treatment to 83.3% after treatment. 3.The mechanism of biofeedback treatment for defecation disorders The theoretical basis of biofeedback is the operation of conditioned reflexes. The training with the help of biofeedback therapy instrument is done through the feedback of proprioception, i.e., volitional control. With repeated application of biofeedback, the body deepens the direct perception of in vivo information, improves sensitivity, and converts indirect perception into direct perception, at which time the biofeedback instrument can no longer be used and still achieve better therapeutic results. After biofeedback treatment, it is suggested that muscle resistance to fatigue is significantly enhanced, and the sensory threshold is reduced, that is, rectal sensitivity and adaptability are improved, which helps to improve constipation and anal incontinence symptoms J. Emmanuel et al. believe that this physical treatment not only affects the condition of the pelvic floor muscles, but also affects the regulation of the brain on bowel function by affecting the neural pathways. 4, biofeedback treatment implementation Biofeedback treatment should be targeted to the selection of therapeutic training methods. Before treatment, the therapist should explain to the patient the physiopathological knowledge of constipation or anal incontinence, the purpose and process of treatment, so that the patient can fully understand the condition and cooperate, and the full communication between the therapist and the patient is also a kind of psychotherapy. Each treatment should last 30 to 60 minutes, 2 to 3 times a week, for 6 to 10 weeks. Child patients are best treated at school age. In the United States, a certification body for biofeedback therapists was established in 1981 to standardize training and improve efficacy, and a group training method is often used to obtain mutual learning among subjects and interaction with the therapist. (1) Training program for constipation due to outlet obstruction The training for constipation due to pelvic floor relaxation syndrome is divided into two stages: the first stage is the pelvic floor muscle relaxation training, the main purpose of which is to reduce the resting pressure of the anal canal; the second stage is the coordination training of the internal and external anal sphincter muscles, and the Vasaval maneuver training is completed in conjunction with breathing and continuously reinforced with the assistance of the therapeutic instrument. The second stage of training is to simulate the sensation of defecation by placing an inflatable balloon in the rectum and gradually reducing the amount of inflation to lower the threshold of defecation sensation and improve rectal sensitivity. (2) Training program for anal incontinence It is particularly valuable for the treatment of patients with anal incontinence after low rectal anastomosis and rectal prolapse, and is more effective than perineal training alone. The training can be divided into three stages: the first stage to improve muscle tone, using the Kegel method of training; the second stage to train the coordination between the sphincter and rectum during the patient’s voluntary anal contraction, using the biofeedback-triggered electrical stimulation training method, to the extent tolerated by the patient, usually with a stimulation intensity of 8 to 20 mA, a stimulation time of 20 minutes and a frequency of 5-10 Hz; the third stage to cause a sense of rectal dilatation The volume threshold starts to dilate the rectum, and as long as the rectum is dilated, the external anal sphincter reflexively contracts to prevent fecal incontinence. 5.Evaluation of biofeedback therapy A comprehensive assessment of the condition of patients with constipation or anal incontinence, and a correct diagnosis of the etiology to select the appropriate indication, is the key to achieving good treatment results. Rhee et al. concluded that patients with pelvic floor incontinence syndrome combined with prolonged sphincter function and elevated rectal maximum tolerance are not sensitive to biofeedback treatment. Post-treatment assessment can be done by symptom scores of constipation and incontinence, defecation diaries and anorectal kinetics. Also the patient’s psychological status and subjective involvement are key to the efficacy of the treatment. Biofeedback, as an emerging field of behavioral medicine, has wide research and promotion value in today’s medical model that emphasizes “biopsychosocial”. With the increase of functional diseases, it is also scientific to emphasize the body’s own self-correction. Although biofeedback research in China started late, it has been widely used in clinical practice. In the future, further research will be conducted on the development of biofeedback trainers, selection of indications, standardization of treatment protocols, assessment of efficacy and mechanisms of biofeedback.