Objective To explore the possible mechanism of Zhizhu Pills（枳术丸） in the treatment of slow transit constipation（STC） with spleen deficiency syndrome. Methods A total of 57 mice were randomly divided into a normal groups with 15 mice

and a the model group

a Zhizhu Pills group and a mosapride group with 14 mice in each group. Mice except for the normal group were given senna leaf for gavage

low-fiber diet

diet restriction and water restriction to prepare mice model STC and spleen deficiency syndrome. After successful modeling

the Zhizhu Pills group was given 9.0 g/（kg·d） by gavage

the mosapride group was given 2.5 mg/（kg·d） by gavage

the model group and the normal group was given 0.1 ml/10 g distilled water by gavage

2 times a day for 7 consecutive days. We observed the general behavior and pathological changes of colonic mucosa of each group of mice

and detected the time of the first feces excretion

the quantity and quality of 6 h defecation

the serum calcium ion concentration and the changes of colonic myoelectric slow wave in vivo. Results The mice in the normal group reacted sensitively

with thick and soft fur on the back

good food appetite

and normal stools. Compared with the normal group

the mice in the model group were sluggish

skinny

poor in appetite

dry

hard and less stools with small particles. The first stool discharge time was significantly prolonged

and the number and quality of stools in 6 hours were significantly reduced. Serum calcium ions concentration was significantly reduced

the slow wave frequency was significantly increased

and the amplitude was significantly reduced（P<0.01）. Compared with the model group

the mice in the Zhizhu Pills group and the mosapride group had sensitive responses

with soft fur on the back

good appetite and normal stool. The first fecal discharge time was significantly shortened

the number and quality of the 6 h defecation were significantly increased

the serum calcium ion concentration was significantly increased

the slow wave frequency was significantly slowed down

and the amplitude was significantly increased（P<0.05 or P<0.01）. Compared with the mosapride group

the serum calcium ions of the Zhizhu Pills group increased

and the slow wave amplitude increased（P<0.05）. Conclusion Zhizhu Pills can improve the defecation of mice with STC and spleen deficiency syndrome

and may increase the concentration of serum calcium ions

thereby regulating the slow wave of the colon and enhancing the intestinal motility.