Blood testing is now included in screening recommendations for colon and rectal cancer

The American Cancer Society now includes an FDA‑approved blood test (Guardant Health’s Shield) as a screening option for average‑risk adults 45+ who won’t or can’t do a colonoscopy or stool test — it’s a simple blood draw done about every three years.
The blood test can boost participation (Guardant reports >90% completion) and may help catch cancers earlier for people who avoid other tests, but it’s less sensitive for early‑stage cancers and precancerous polyps, so colonoscopy remains the gold standard.
The update also adds new at‑home stool tests (Cologuard Plus, ColoSense) and reaffirms starting screening at 45 through about age 75 — best to talk with your doctor about which option fits you.