Inclusion Criteria:  Person 18 years of age or older Person with colorectal cancer in the context of IBD Person who has received complete information on the organization of the research and who has signed an informed consent Person affiliated to a social security plan or beneficiary of such a plan.  Exclusion Criteria:  Person referred to in articles L. 1121-5, L. 1121-7 and L1121-8 of the public health code: Pregnant woman, parturient or nursing mother Minor (not emancipated) Adult person subject to a legal protection measure (guardianship, curatorship, safeguard of justice) Person of legal age who is unable to express his or her consent Person deprived of liberty by a judicial or administrative decision, persons subject to psychiatric care under articles L. 3212-1 and L. 3213-1.