Abstract： BACKGROUND: Constipation, especially that caused by spleen insufficiency in transportation, often not responses to common purgatives, however,the therapy to strengthen the spleen and regulate qi so as to promote transportation and dredge stasis may be an ideal way to resolve the problem.OBJECTIVE: To investigate the effect of zhizhu decoction, a classic famous prescription, on gastric motility of mice with spleen insufficiency constipationDESIGN: A randomized controlled trial.SETTING: Department of Traditional Chinese Medicine (TCM) of Guangdong Medical College and Spleen-stomach Institute of Guangzhou University of Traditional Chinese Medicine.MATERIALS: The experiment was completed from June to December2002 at Spleen-stomach Institute of Guangzhou University of Traditional Chinese Medicine. Totally 328 NIH mice of general grade were chosen.METHODS: Mouse models with spleen insufficiency constipation were set up by irregular diet and overstrain combined with water deprivation. The influence of zhizhu decoction in large, middle and small doses on defecation in both spleen insufficiency mice and normal mice was investigated, taking Chinese patent drug bianmi tong (bowel-relaxing) as a positive control. In observation of normal mice defecation, there were five groups of large dose,middle dose and small dose of zhizhu decoction, bianmi tong and normal control. In observation of defecation of spleen insufficiency constipation mice, there were six groups: the above five and a natural recovering. In observation of loading mice trial, besides the above five groups, there was an atropine group. After administration, the time when the mice first defecated dark stool, the number of stool grains and the stool quantity were observe;and the percentage of small intestine advance was calculated.MAIN OUTCOME MEASURES: [1] Observation of the effect of zhizhu decoction on the defecation in both normal and spleen insufficiency mice.[2] The influence of zhizhu decoction on bowel advance in both normal and atropine loading miceRESULTS: Totally 328 mice were involved in the trial and 319 entered into the final result analysis, the other 9 died because of mistake in administration by gavage. The effect of zhizhu decoction on the defecation: [1] For normal mice, compared with the distilled group, in the zhizhu decoction groups of various doses the time when the mice first defecated dark stool was obviously reduced, and the number of stool grains and stool quantity were obviously increased, but the effect in the large and middle dose groups was best. [2] Compared with the normal group, in the model group the time when the mice first defecated dark stool was obviously increased, and the number of stool grains and stool quantity were obviously decreased. Zhizhu decoction in large and middle doses could obviously reduce the time when the mice first defecated dark stool, and increase the number of stool grains and stool quantity, the effect was better than that of the control drug bianmi tong. The influence ofzhizhu decoction on intestinal advance in mice: [1]Zhizhu decoction in various doses could obviously increase the rate of intestinal advance compared with distilled water group for normal mice. [2]Adding atropine load could reduce the rate of intestinal advance compared with the normal control group, and the percentage in all zhizhu decoction groups was obviously increased compared with the atropine group.CONCLUSION: Zhizhu decoction can reduce the time when the mice first defecated dark stool, increase the number of stool grains and stool quantity were obviously increased to both normal mice and mice with spleen insufficiency mice; it can also increase the intestinal advance rate in normal mice, and had a good antagonism against the inhibition of atropine to intestinal advance. In the trials the effect of zhizhu decoction in large and middle doses was more obvious, with a certain dose-effect relationship, the effect was better than that of the control drug bianmi tong.