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 currently the first-line treatment method for bowel disorders.
1.The concept of biofeedback training
Biofeedback training is the use of biofeedback instrument to amplify and display the physiological signals that are not easily perceived by people, so that the subjects can learn and practice repeatedly to become familiar with and
Through learning and repeated practice, the subject can become familiar with and master the physiological changes, form and maintain the self-control ability of specific parts of the body, and improve the 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 motivation” and consciously control the body. Biofeedback training is a continuous learning process of “knowing oneself” and “changing oneself”. The treatment of defecation disorders is mainly realized through electromyography-mediated or pressure-mediated biofeedback, in which subjects can intuitively perceive the functional state of their pelvic floor muscles during defecation and learn how to appropriately relax and contract the pelvic floor muscles.
2.The development of biofeedback therapy instrument
According to the development of the processing method of the collected signal, it can be roughly divided into three stages. The first stage uses the Perryanal intra-anal surface
The first stage uses Perryanal intra-anal surface electromyography probe to collect signals and then amplify and filter them into digital signals and then trace the curve on the screen and hear the “bla bla” sound of muscle contraction.
The first stage uses a Perryanal surface myoelectric probe to collect the signal, amplify and filter it into a digital signal and then trace the curve on the screen and hear the “bla bla” sound of muscle contraction. This phase of the procedure is performed with a polysomnographic recorder, which has the disadvantages of signal distortion, difficulty in patient understanding, and lack of training programs, and therefore patient compliance is poor, which affects the effectiveness of the procedure. The authors treated 30 patients with pelvic floor relaxation syndrome using this stage of instrumentation, and 30% of them showed significant relief after treatment…. The second stage of development was to optimize the hardware based on the first stage, and to transform the boring and difficult signal recording into a humanized animation, so that the patients could have a better knowledge of their abnormal signals through the therapist’s explanation, and could have better human-computer interaction, even for the training of children with defecation disorders. In the third stage, as the research on pelvic floor physiology deepened, targeted training programs were emphasized, and the pelvic biofeedback therapy device was developed using triggered electrostimulation biofeedback technology. In China, Sun Daqing et al. used this method to treat 36 cases of pediatric defecation disorders, with an effective rate of 72.7% to 82.4%, and compared with the second stage of the device, feedback therapy combined with electrical stimulation, especially for lowering the rectal sensory threshold is more effective, the rate of contractile reflexes of the anal canal of children with fecal incontinence increased 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 operational conditioned reflex. With the training of biofeedback therapy instrument, the training is done through the feedback of proprioception, i.e., volitional
control to complete. With repeated application of biofeedback, the body’s direct perception of in vivo information is deepened and sensitivity is increased, so that indirect perception is transformed into direct perception, and at this time, the biofeedback instrument can no longer be used and still achieve better therapeutic results. According to Sun Daqing et al, the biofeedback treatment suggests that the muscle resistance to fatigue is significantly enhanced, and the sensory threshold is lowered, which means that rectal sensitivity and adaptability are improved, which helps to improve the symptoms of constipation and anal incontinence.
4. Biofeedback treatment implementation
Biofeedback treatment should be targeted to the treatment training method. Before treatment, the therapist should explain to the patient the physiology of constipation or anal incontinence.
Before the treatment, the therapist should explain the physiology, purpose and process of constipation or anal incontinence to the patient, so that the patient can fully understand the condition and cooperate with the treatment. Each session should last 30-60 minutes, 2-3 times a week, for 6-10 weeks. Childhood patients are better off at school age. In the United States, a certification body for biofeedback therapists was established in 1981 to standardize training and improve efficacy, and group training of subjects is often used to obtain mutual learning and interaction with the therapist.
(1) Training program for outlet obstructive constipation
The first stage is pelvic floor muscle relaxation training, which aims to reduce the resting pressure of the anal canal; the second stage is the coordination of the internal and external anal sphincter muscles, and the Vasaval maneuver training, which is performed with the assistance of the therapeutic instrument. In the second stage, the training is to lower the threshold of defecation sensation and improve rectal sensitivity by placing an inflatable balloon in the rectum to simulate the sensation of defecation and gradually reducing the amount of inflation.
(2) Training program for anal incontinence
It is particularly valuable in the treatment of patients with rectal incontinence after low rectal anastomosis and rectal prolapse and is more effective than perineal training alone. The second stage is to train the coordination between the sphincter and the rectum during voluntary anal contraction, using biofeedback-triggered electrical stimulation to the extent tolerated by the patient, usually with a stimulation intensity of 8-20 mA, a stimulation time of 20 minutes, and a frequency of 5-10 Hz. -In the third stage, the rectum is dilated at the volumetric threshold that causes the sense of rectal dilatation, and as soon as the rectum is dilated, the external anal sphincter is reflexively contracted to prevent fecal incontinence.
5.Evaluation of biofeedback therapy
A comprehensive assessment of the condition of patients with constipation or anal incontinence, a correct diagnosis of the cause, and the selection of appropriate indications are the keys to achieving good results.
The key to achieving good treatment results is to make a correct diagnosis of the cause and select the appropriate indication. Rhee et al. concluded that patients with pelvic floor incontinence syndrome combined with prolonged sphincter function and increased maximum rectal tolerance are not sensitive to biofeedback treatment. The post-treatment evaluation can be done through symptom scores of constipation and incontinence, defecation diaries, and anorectal kinetics. The patient’s psychological status and subjective involvement are also key to the outcome.
6. Outlook
Biofeedback, as an emerging field of behavioral medicine, has a wide range of research and promotion value in today’s medical model that emphasizes “biopsychosocial”.
The value of biofeedback as an emerging field of behavioral medicine is widely researched and promoted in today’s medical model emphasizing “biopsychosocial”. With the increase of functional diseases, it is also scientific to emphasize the self-correction of the human body. Biofeedback in China
Although the research in China started late, it has been widely applied 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.