The frequency and number of fecal excretion, water content and the layer of acid mucin secreted by epithelium of the NAR-treated loperamide-administered group was significantly higher than that in the loperamide-administered group, suggesting that NAR produces a laxative effect and alleviate the symptoms of loperamide-induced constipation. The gene discussed is MUC5AC; the disease is constipation disorder.