The present invention relates to a method for improving adsorption on the gastrointestinal mucous layers of one or more selected from polyethylene glycol, polyethylene oxide, and polyoxyethylene polypropylene copolymer wherein the average number of repeating oxyethylene units of one ethylene oxide chain length is 17 or greater. It is possible to enhance pharmacological effects by using the present invention with drugs that have anti-H. pylori activity.