This study is designed as an early-feasibility, single-center, single-blinded, randomized controlled trial (RCT), in which subjects are consented, undergo a baseline assessment, and receive taVNS or sham-taVNS treatment twice a day (8 a.m. and 8 p.m.) for 30 minutes each time for a period of 4 weeks. The taVNS and sham-taVNS treatment was applied using the commercially-available Transcutaneous Electrical Applicator device (Model SNM-FDC01, Ningbo MedKinetic Medical Device Co., Ltd.) with the skin electrodes placed bilaterally on auricular concha. The patients are requested to score the abdominal pain (using VAS) and complete BSFS, IBS-SSS, IBS-QOL, SAS, and SDS forms every week and fill out the bowel diary during taVNS or sham-taVNS. Emergency medications (Macrogol 4000 and pinaverium) are permitted for use when the patient cannot tolerate symptoms of constipation and abdominal pain.
This study aims to investigate the effects and possible mechanisms of transcutaneous auricular vagal nerve stimulation (taVNS) on abdominal pain and other symptoms in patients with IBS-C.