Clinical Trials of N-acetyl Glucosamine Capsule for IBS-D Treatment

Inclusion Criteria:

• Voluntarily signed the informed consent form.

• Man or woman, aged 18 to 65 years, inclusive.

• Based on the Roman III diagnostic criteria for diagnosis of IBS-D subjects, recurrentabdominal pain accompanied with abdominal discomfort or not, monthly attack within thepast 3months at least 3 days. With two or more of the following three kinds ofsymptoms: At least a portion of the time abdominal pain or defecate increase when discomfort. At least a portion of the time abdominal pain or the row of loose stools when discomfort. At least a portion of the time abdominal pain or discomfort improved after defecation. Symptoms for at least 6 months before diagnosis.

• Screening/import period pain intensity scores of the NRS week mean value are 3.0 plusand the days which at least more than one time a stool type are 6 or 7 type over 2days per week.

• During the screening period，patients should answer the questions of electronic logcompletely following the requirements for 10days or more.

• Patients are willing to stop drugs for abdominal symptoms or diarrhea which are inviolation of the scheme, and take medicine prescribed in the scheme.

• Patients agree to not change the lifestyle significantly that may affect the symptomsof IBS-D from signing up the Informed Consent Form to the last experiment.

• The illness recured after a normal colonoscopy report within one year that wasprovided by this hospital or a grade first class teaching hospital, include polyp ofcolon (less than 3mm,the number of less than 5) patients who taked therapeuticendoscopy and recurrenced within one year; or those that get a normal colonoscopyreport in this hospital or a grade first class teaching hospital before screening buthave a history of bowel preparation, should be chosen when next attack.

Exclusion Criteria:

• History of organic gastrointestinal diseases: Chronic pancreatitis (cp), inflammatorybowel disease, intestinal tuberculosis, malabsorption syndrome, celiac disease,gastrointestinal tumor, or other organic diseases etc.

• History of abdominal and pelvic surgery ( not including appendectomy and intestinalpolyposis (<3mm) after treatment within one year ).

• The non-intestinal disease of digestive system such as Peptic ulcer, tuberculousperitonitis, cirrhosis etc.

• Heart, lung, kidney and other important organs have severe lesions, immune regulatorydisease, metabolic disease (diabetes, thyroid disease) or malignant tumor,reproductive system diseases such as ovarian cysts, endometriosis, etc.

• Laboratory tests or Electrocardiogram were significantly abnormal, and judging by theresearchers may damage the patient safety or successful completion of the clinicalresearch: Male hemoglobin <120g/L, female hemoglobin <100g/L; Male serum creatinine≥133umol/L, female serum creatinine≥124umol/L; or creatinine clearancerate≤60ml/min; Chronic liver disease and/or abnormal liver function, defined as AST (aspartateaminotransferase) > 1.5 x ULN (Upper Limit Of Normal) and/or ALT (alanine aminotransferase) > 1.5 x ULN and/or total bilirubin > 1.5x ULN;

• Serious psychiatric patients( Hamilton Depression Scale scores>20).

• History of drug abuse or alcohol abuse.

• Allergic to this study drug.

• Concomitant medication is unable to stop or use continuously for more than a week butaffect the gastrointestinal movement and function in the experiment, such asantibiotic drugs, the drugs of regulating the intestinal microecology, parasympatheticinhibitors, muscle relaxants, antidiarrheal, opiates, etc.

• Do not fill in the electronic log of one week before entering the group (-1 week)completely.

• Pregnant or lactating women

• Is participating in clinical trials or have finished it less than 3 months.

• Other researchers think not suitable for the list.