These results confirmed that overexpression of 5-HT and 5-HT3R expressions in the colon tissue of IBS patients is closely related to visceral hypersensitivity and further suggested that both EA and Mox treatments may relieve symptoms result from visceral hypersensitivity by downregulating of 5-HT and 5-HT3R expressions. Here, HTR3A is linked to irritable bowel syndrome.