Objective To explore the effect and functional mechanism of eye-acupuncture therapy on the diarrhea irritable bowel syndrome（D-IBS）.Methods Forty Wistar rats were randomized into four groups

control group

model group

pinaverium bromide group

and eye-acupuncture group

with 10 in each.We used chronic stress in combination with binding to make D-IBS models.The eye-acupuncture group was treated with eye-acupuncture at the auricular points Lower-jiao

Large intestine

Liver

and Spleen

and the pinaverium bromide group was treated with pinaverium bromide for intragastric feeding

for 7 days.The histopathological changes of colon were observed by HE staining

the Neurokinin1（NK1） mRNA expression changes were detected by realtime-PCR

and the colic NK1 protein expression changes were determined by immunohistochemical method.Results The result of HE staining showed that there was no morphological changes of colic tissues.Compared with the control group

the NK1 mRNA expression of colic tissues in the model group was significantly increased（P<0.01）.Compared with the model group

the NK1 mRNA expression of colic tissues in the eye-acupuncture group was significantly decreased（P<0.01）.Compared with the model group

the NK1 mRNA expression of colic tissues in the pinaverium bromide group was without statistical significance（P>0.05）.NK1 immunoreaction positive cells were existing in the colonic mucous layer

lumen of gland

intermuscular plexus

and submucous plexus.Compared with the control group

the colic NK1 protein expression in the model group was significantly increased（P<0.05）;compared with the model group

the colic NK1 protein expression in the eye-acupuncture group and pinaverium bromide group was significantly decreased（P<0.05）.Conclusion Eye-acupuncture could effectively decrease the colic NK1 expression of D-IBS model rats

playing a therapeutic role in treatment of D-IBS.