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 colorectal cancer (CRC) (\< 50 years old \[yo\])
* 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) 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 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
* Removal of more than 50% of colon or presence of ileostomy
* Enteral feeds or total parenteral nutrition (TPN)
* Diagnosis of inflammatory bowel disease

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 5/17/2024. Questions regarding updates should be directed to the study team contact.