The present invention relates to a purgative composition containing polyethylene glycol and sodium picosulfate, wherein the stability of sodium picosulfate is improved by adding a pH controller. According to the present invention, the purgative composition ensures the stability of medicinal ingredients and has a great advantage of having a small dose even while showing a bowel cleansing rate greater than or equal to a commercial preparation, which should be taken in a large dose. In addition, according to the present invention, the composition has high compliance due to a good taste.
