Inclusion Criteria:

• Patients at least 18 years of age.
• Individuals diagnosed with Lynch syndrome (mutation in MLH1, MSH2, MSH6, PMS2, EPCAM) or suspected Lynch syndrome or individuals diagnosed with early onset CRC (< 50 years old).
• Colonoscopy scheduled +/- 90 days.

Exclusion Criteria: 

• Individuals who have not agreed to participate and have not signed the study consent form.
• Patient has known cancer (Stage I-IV) 5 years prior to current sample collection (not including basal cell or squamous cell skin cancers; if patient has not been seen or if information is not available, the patient is still eligible).
• Patient has received chemotherapy class drugs for the treatment of cancer in the 5 years prior to current sample collection.
• Patient has had any abdominal radiation therapy prior to current sample collection.
• Patient had therapy to the target lesion with intent to completely remove or debulk the lesion prior to sample collection (examples include polypectomy, EMR, ESD, surgical resection, trans anal excision).

Additional Stool Exclusions:

• Bowel prep < 7 days prior to stool collection.
• Oral or rectal contrast given within 7 days prior to stool collection.
• Removal of more than 50% of colon or presence of ileostomy.
• Enteral feeds or TPN.
• Diagnosis of inflammatory bowel disease.

Eligibility last updated 9/28/21. Questions regarding updates should be directed to the study team contact.