2.2. Patient population and eligibility criteria

Inclusion criteria:

Patients meet the the Rome III diagnostic criteria for IBS-D;

Those who agree to participate in this study and are willing to sign informed consent.

The age ranged from 18 to 65 years old.

Exclusion criteria:

Under 18 years old or over 65 years old;

A woman who is pregnant or is preparing for pregnancy, and lactating.

Intestinal organic diseases, such as inflammatory bowel disease, intestinal tuberculosis, colon polyps;

Patients with severe cardiovascular and cerebrovascular diseases, liver, kidney, hematopoietic system diseases and tumors;

There were records of digestive tract operation;

Patients with severe primary diseases and mental disorders;

Patients with allergic history or drug and food allergy during the test period;

Those who do not sign informed consent

Those who do not meet the inclusion criteria, fail to use drugs according to the regulations, cannot judge the curative effect or incomplete data, which affects the evaluation of efficacy or safety.

The researchers consider it inappropriate to conduct this clinical trial.