Inclusion Criteria:

• Patients at least 18 years of age
• Individuals diagnosed with Lynch syndrome (mutation in MLH1, MSH2, MSH6, PMS2, EPCAM) or colorectal cancer (CRC) with suspected Lynch syndrome or individuals diagnosed with early onset CRC (<55 years old)
• Colonoscopy/flexible sigmoidoscopy (flex sig) scheduled +/- 90 days from sample collection
• Patient has agreed to participate and has signed the study consent form

Exclusion Criteria:

• Patient has known cancer (stage I-IV) within 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 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 (non-hyperplastic) lesion with intent to completely remove or debulk the lesion prior to sample collection [examples include snare polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), surgical resection, trans anal excision]
• Patient has prior diagnosis of non-lynch hereditary colon cancer syndrome [familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), Peutz-Jeghers syndrome (PJS), juvenile polyposis syndrome (JPS), PTEN, POL]
• ADDITIONAL STOOL EXCLUSIONS:
• Bowel prep <7 days prior to stool collection
• Oral or rectal contrast given within 7 days prior to stool collection
• Presence of ileostomy
• Enteral feeds or total parenteral nutrition (TPN)
• Diagnosis of inflammatory bowel disease