Biofeedback therapy for constipation

Forty percents of people with constipation have straining problems during defecation. The muscle involved in passing stool does not coordinate correctly with the anal sphincter, also known as Dyssynergic defecation. Apart from having symptoms like typical constipation, this group also has a sensation of incomplete evacuation or not getting everything out after going to the toilets, requiring digital rectal stimulation and excessive straining.

Proper straining involves tensing abdominal muscles with appropriate force to move stools into the rectum. Meanwhile, anal sphincter muscles must relax to allow the expulsion of the feces. People with incorrect straining typically have a contraction of the anal sphincter while straining, or their anal sphincter may fail to relax enough to allow the expulsion of stool. In some people, improper contraction of abdominal muscles may occur in concert.

These conditions can be diagnosed with anorectal manometry with a Balloon expulsion test or defecography.

Anorectal manometry

Anorectal manometry involves inserting a small catheter to record the contraction and relaxation of the anal sphincter. The results will show in number and graph formats. This method can measure muscle relaxation during straining to defecate and contraction force for continence (in patients with bowel incontinence). It can also evaluate whether the person strains properly or overstrains. Some people with constipation have rectal hyposensation, resulting in the lack of the urge to defecate despite the right amount of stools in the rectum. They will have less frequent bowel movements, causing retained stools in the rectum and leading to hardened feces. As a result, constipation occurs. Anorectal manometry can measure the sensing function of the rectum. The test takes about 60 minutes, requiring an enema at least 2 hours before the test begins.

Treatment

Treatment for improper straining is a biofeedback therapy. The expectations for this approach are that people can pass stools with minimal or no laxative use and without digital stimulation.

Biofeedback training allows patients to perceive their characteristics of fecal straining in real-time by watching the visual feedback on the monitor and their muscle activity while bearing down. They will learn to remember the feeling of how to strain correctly, which requires learning time, and patients need to continue practicing at home. The training takes 45 – 60 minutes per session, not longer than 1 - 2 weeks apart, for at least 2 – 4 times. A tube used in Biofeedback has the same size as a catheter used in an anorectal manometry, which is 4 – 6 millimeters wide and no deeper than 10 centimeters. Biofeedback can be used to treat patients with rectal hyposensation as well.

Biofeedback therapy mainly focuses on solving fecal straining problems, which are present in as much as 40% of people with constipation. However, in constipated people with not just straining problems but also gastrointestinal hypomotility and other disorders, after the straining issues are alleviated, there may still be a need to continue taking some types of laxatives to help with the contraction of the intestine or softening the stools for better bowel movement, which will allow patients to strain properly without passing out in a toilet, and lessen a feeling of incomplete evacuation and the urge for a digital rectal stimulation. Eventually, patients will spend less time for bowel movements.