As for this research，we want to find whether the intestinal microecology (flora, peptidoglycan fragments) have certain distribution characteristics in colorectal diseases; whether it can predict the development of disease/as a prognostic indicator.

We even want to find whether it can predict the development of disease/as a prognostic indicator.

Inclusion Criteria:

• people who is going to get the colonoscopy examination

Exclusion Criteria:

• people who was diagnosed as one cancer，expect for CRC; who has had the antibiotics or the medicine that treats for colorectal disease, except for medical probiotics, in one month; who has had the laxative and the colonscopy in one week; who had a operation in three month.

2500