Effect of Transcutaneous Auricular Vagal Nerve Stimulation on Chronic Constipation

The worldwide prevalence of chronic constipation (CC) is 15%, and women are more likely to develop the disease than men. CC have a significant impact on quality of life and increase the burden of national health insurance. The conventional medication treatments are primarily symptom-specific and have limited efficacy. Previous small sample study had shown the therapeutic potential of transcutaneous auricular vagus nerve stimulation (taVNS) for irritable bowel syndrome with constipation (IBS-C). The aim of this study was to investigate whether taVNS could improve defecation condition and constipation symptoms in patients with CC.

Inclusion Criteria:FC or IBS-C patients aged 18-75 years who meet the diagnostic criteria for Rome IV;Complete spontaneous bowel movements (CSBMs) per week < 3;No constipation medication used for at least 2 weeks prior to enrollment, not participated in clinical trials in the past three months, and no abnormal colonoscopy within the past 12 months in those with alarm symptoms.Exclusion Criteria:Have cognitive impairment, psychiatric disorders, or conditions that may affect patient cooperation;Have a cardiac pacemaker implantation or other electronically implanted devices;Prior taVNS treatment;History of colorectal surgery, except for simple appendectomy;Severe cardiovascular, hepatic, or renal disease;Known malignancy;Secondary constipation caused by medications and other diseases;Pregnant or lactating women;Refusal to sign an informed consent.