Noninvasive electrical neuromodulation involving vagus nerve mechanism for functional constipation and irritable bowel syndrome with constipation.

Functional constipation (FC) and irritable bowel syndrome with constipation (IBS-C) are prevalent disorders of gut-brain interaction with limited effective treatments. The vagus nerve exerts considerable influence on the gastrointestinal (GI) tract, indicating that noninvasive electrical neuromodulation targeting this nerve could provide a promising therapeutic avenue for both FC and IBS-C. This review explores several emerging noninvasive neuromodulation techniques involving the vagus nerve, such as transcutaneous auricular vagal nerve stimulation, percutaneous electrical nerve field stimulation, and transcutaneous electrical acustimulation. The clinical applications of these methods in managing FC and IBS-C are evaluated. Existing evidence supports the efficacy and safety of noninvasive neuromodulation in relieving symptoms of these conditions. Future investigations should aim to refine these techniques, advance device technology, and further clarify the mechanisms of action.