In this study,we collected the prescriptions of Professor Liu Fengbin used for the out-patients with irritable bowel syndrome(IBS),counted the usage frequency of the herbs and core-combination herbs in the prescriptions,analyzed the medication principles of Professor Liu Fengbin,and mined the new recipes for IBS by the methods of association rule mining and complex system entropy clustering presented in the Traditional Chinese Medicine Inheritance Support System.The results showed that Professor Liu is experienced in treating IBS based on liver-spleen differentiation,mainly applying the therapies of invigorating spleen and replenishing qi,soothing liver and regulating qi,also using the methods of resolving dampness,alleviating depression,relieving pain and activating blood,and prescribing the basic recipe of Chai Shao Sijunzi Decoction.The medication principles of Professor Liu Fengbin for the treatment of IBS will be beneficial to the further exploration of the syndrome pattern distribution of IBS and new recipes for IBS.