NEW YORK (Reuters Health) - Transcutaneous electrical acustimulation (TEA) at acupoint ST36 on the leg improves functional constipation by enhancing rectal sensation and parasympathetic activity, a small study suggests.
"The role of rectal sensitivity in contributing to pathophysiology of functional constipation is not established; however, recent studies have reported rectal hyposensitivity in patients with functional constipation," researchers explain in Clinical and Translational Gastroenterology.
TEA combines neuromodulation and electroacupuncture. It delivers weak electrical current to acupuncture points near peripheral nerves via electrodes placed on the skin using known parameters to improve autonomic functions.
TEA has been shown to be effective in treating several functional gastrointestinal diseases, including gastroesophageal reflux disease, functional dyspepsia and constipation.
These studies have consistently demonstrated TEA-induced improvement in GI motility and rectal sensation by enhancing parasympathetic activity.
However, it's unclear whether TEA can improve both constipation and reduced rectal sensation in patients with chronic constipation.
To investigate, Dr. Jiande Chen of the University of Michigan in Ann Arbor and colleagues evaluated the effect of acute TEA on rectal sensation; the effects of chronic TEA on rectal sensation and constipation; and the mechanisms involving autonomic functions in patients with functional constipation according to the Rome IV definition and reduced rectal sensation.
In an acute study, they performed motility and sensation tests in 53 adults with constipation who were treated with TEA at ST36 or sham points. In a chronic study, 18 patients underwent two weeks of TEA or sham-TEA in a crossover design. TEA or sham-TEA was performed for one hour twice daily (morning and evening).
Compared with sham-TEA, chronic TEA increased spontaneous bowel movements (3.72 vs. 2.00 per week; P<0.0001) and significantly reduced constipation symptoms and increased quality of life (P<0.05), the researchers report.
Acute TEA reduced the sensation threshold in response to rectal distention for urge of defecation and maximum tolerable volume (P<0.05 vs baseline) and chronic TEA reduced the sensation thresholds for first sensation and desire of defecation, and decreased the threshold volume to elicit the rectal anal inhibitory reflex (P<0.05), they observed.
Both acute and chronic TEA increased parasympathetic activity (P<0.05).
In an email to Reuters Health, Dr. Chen said the results show that TEA at ST36 "can be used to effectively treat functional constipation. It can improve rectal sensation, which has rarely been reported in other therapies. It can be self-administrated at home and is safe, and thus may benefit a large percentage of patient population."
Patients were "receptive and adherent; four out of 24 patients were allergic to stimulation electrodes (normal EKG electrodes) and quit the study," Dr. Chen added.
Dr. Chen cautioned that this therapy remains investigational and the next step is to "perform a multicenter study with a large sample size."
The study device was made by Ningbo Maida Medical Device Company in China. The study was not funded and the authors have declared no conflicts of interest.
SOURCE: https://bit.ly/3Dqb2Hj Clinical Translational Gastroenterology, online March 28, 2022.
Reuters Health Information © 2022
