In radioactive examination, abdominal radiograph is the first choice of the urinary system examination. A high quality abdominal radiograph can provide better information. In gastrointestinal radiography, the cleanliness of intestinal has direct effect on disease diagnosis. The traditional cleaning enema method is inconvenient and it hardly cleans the whole intestinal. Different cathartics have different effects. At last, we compared the effect of the infusion of senna, decoction of senna and mannitol for abdominal radiograph with 198 patients from February 2007 to December 2007 and made a statistical analysis.The result showed that senna diarrhea bowel preparation for the laxative was the best option