HTR3A and irritable bowel syndrome: The abnormal expressions of 5-HT, 5-HT3R, and 5-HT4R in both groups were significantly improved after the treatments (all P < 0.05), and EA was superior to Mox in regulating the abnormally decreased 5-HT4R expression in IBS patients with constipation (P < 0.05). Conclusion.