Objective To make an individualized treatment plan for newly diagnosed irritable bowel syndrome by means of evidence-based medicine. Methods After clinical problems were put forward, systematic reviews and randomized controlled trials were collected from The Cochrane Library (Issue 3, 2008) and PubMed (1990 to 2008). Treatment protocol was produced by combining the evidence and the values of the patient. Results A total of 114 RCTs and 21 systematic reviews were identified. A rational treatment plan was made upon a serious evaluation of the data to control symptoms and improve the quality of life for the patient. After a sixteen-month follow-up, the plan proved to be optimal. Conclusion The treatment efficacy in diagnosed irritable bowel syndrome has been improved by determining an individualized treatment plan according to evidence-based methods.