Objective To explore the effects of with antibiotics-probiotics in patients with diarrhea-predominant irritable bowel syndrome.Methods All of 86 patients with D-IBS were divided into 3 groups.The patients in Group A received sequential treatment with antibiotics,Pinaverium Bromide and Glutamine enteric-coated capsules in the first week,and then followed with Pinaverium Bromide and Glutamine enteric-coated capsules and probiotics for another 7 weeks.The patients in Groups B received with Pinaverium Bromide,Glutamine enteric-coated capsules and probiotics for 8 weeks.The patients in Groups C received with Pinaverium Bromide and Glutamine enteric-coated capsules for 8 weeks.The gastrointestinal symptom scores were documented respectively before and after the treatment.Results The duration of abdominal pain during and after the were shortened significantly when compared to those prior to the treatment,the frequency of abdominal pain and the proportion of abnormal stool decreased significantly in all the groups during and after the treatment.The lower GI symptom score of three groups decreased significantly in the 4th week,the scores of Group A was significantly lower than that of Group B and C.And the effect maintained for 4 weeks after the drug withdrawal.Conclusion All the treatments greatly improved the lower GI symptoms in D-IBS suffers.However,the was better in relieving the lower GI symptoms comparing with adjusted and general treatment,and maintained remission longer.