PROBLEM TO BE SOLVED: To provide an X-ray examination method for the digestive tract, resolving a problem of diagnosis by a conventional bad pretreatment of X-ray examination of injection into the intestines, raising convenience of administration and not imposing a burden on patients, especially patients of disabled body and aged persons and to obtain a medicine for pretreatment used therefor. SOLUTION: This contrast ability improver of X-ray contrast media for digestive tract examination is characterized by comprising an enterokinesis promoter as an active ingredient. The compounding agent for intestinal tract washing is characterized by comprising an intestinal tract washing agent and an enterokinesis promoter as active ingredients. The kit or packed article for intestinal tract washing is characterized by using both an intestinal tract washing agent and an enterokinesis promoter.
