Optimization of Transcutaneous Electrical Acustimulation (TEA) Modalities for Treatment of IBS-C

This study aims to discern whether acute, single-session Transcutaneous Electrical Acustimulation (TEA) at acupuncture points ST36 or PC6 will relieve abdominal pain induced by rectal distension in patients with IBS-C. Each study participant will have 5 research visits at the Michigan Medicine GI physiology lab. During these visits, participants will undergo a procedure similar to Anal Rectal Manometry (ARM) performed by the GI physiology lab staff. TEA is similar to this procedure as it uses the barostat device and is performed by the GI physiology lab staff. This device has a rubber catheter that will be inserted 5-15 cm into the rectum of the study participant. Then the GI physiology staff will inflate the catheter. Study participants will then be asked when they can sense the catheter. Then the GI physiology staff will continue to inflate the catheter and the study participants feel discomfort (described as the 'urge to defecate'). Then the study participant will be asked to pass the balloon (like they would pass a bowel movement). The difference between ARM procedure and the study procedure is that there will be stimulation of acupuncture point ST36 which is below the knee cap or stimulation of acupuncture point PC6 which is just above the wrist. For this study, this mild electrical stimulation will occur simultaneously with the barostat procedure. At each visit there will be stimulation of only one of the points at either 100Hz or 25Hz. These are the potential combinations: ST36 100Hz, ST36-25Hz, PC6-100Hz, PC6-25Hz, Sham-TEA. The frequency and position combination (or sham visit) is randomly assigned. The randomization determines the order in which the study participant moves through the study. Every study participant will, in the end, complete one visit at each frequency and a sham visit. The study participant will also complete surveys at the appointment. The TEA device is classified by the FDA as a non-significant risk device.