Irritable bowel syndrome (IBS) is a very common gastrointestinal disorder characterized by chronic abdominal discomforts including distension, abdominal pain and altered bowel habits. This patient was presented with chronic diarrhea for twelve years and severe colic pain over lower abdomen. The diagnosis of diarrhea-predominant irritable bowel syndrome was made. Because IBS is a chronic condition with no known cure with Western medication, she visits oru OPD for Chinese medication. She is successfully treated by focusing on supplement the vital energy for the spleen, adjustment of body fluid and using ShenLingBaiJu powder.