Written by Amara Diallo
New American Cancer Society guidelines add at-home stool tests and a blood draw to the screening menu — a timely shift as colorectal cancer becomes the leading cancer killer of adults under 50.
For decades, the colonoscopy has been the gold standard of colorectal cancer screening — and for many people, the prospect of the procedure, the preparation, and the time off work has been enough to put it off indefinitely. That avoidance has had a steep cost. More than 20 million Americans who are eligible for colorectal cancer screening have never been tested as recommended. And in a troubling trend that has alarmed oncologists, colorectal cancer has now become the top cancer killer of adults under the age of 50 in the United States.
In May 2026, the American Cancer Society released a landmark update to its colorectal cancer screening guidelines — the most significant expansion of screening options in years. The core message is straightforward: the best screening test is the one you will actually complete. And now, there are more options than ever to make that possible.
The updated guidelines, published in CA: A Cancer Journal for Clinicians, reaffirm that average-risk adults should begin screening at age 45 and continue through age 75. But they add three new or updated testing pathways alongside the traditional colonoscopy.
The first is an updated version of Cologuard, the at-home stool DNA test that many Americans are already familiar with. You collect a stool sample at home, mail it to a laboratory, and receive results without setting foot in a clinic. The new next-generation version analyzes stool for specific DNA markers and traces of blood, and is recommended every three years for average-risk individuals.
The second is a brand-new at-home test called ColoSense, which analyzes stool for RNA markers and hemoglobin rather than DNA. Both Cologuard and ColoSense demonstrate high sensitivity for detecting colorectal cancer and are now formally endorsed as preferred screening options. For many people, the ability to complete a screening test privately, at home, on their own schedule, removes the single biggest barrier to getting tested.
The third addition is a blood-based test — the Shield test — which detects tumor DNA circulating in the bloodstream. The ACS guidelines include it as an option specifically for individuals who decline or cannot complete the stool-based tests. Importantly, the guidelines note that blood-based tests are less sensitive than stool tests for detecting early-stage cancers and precancerous growths, so they are positioned as a fallback rather than a first choice. Any positive result from any of these tests still requires a follow-up colonoscopy, ideally within six months.
Why does this matter so urgently right now? Colorectal cancer is one of the most preventable cancers in existence. When caught at an early, localized stage, the five-year survival rate exceeds 90 percent. The challenge has never been the treatment — it has been getting people to screen before symptoms appear. Symptoms, when they do arrive, often signal disease that has already progressed.
The rise of colorectal cancer in younger adults is particularly alarming. Rates in people under 50 have been climbing steadily since the 1990s, and researchers are still working to understand why — with diet, microbiome changes, obesity, and sedentary lifestyles all implicated as contributing factors. The ACS lowered its recommended screening start age from 50 to 45 in 2018 precisely because of this trend, and the 2026 guidelines reinforce that urgency.
The practical guidance for readers is simple: if you are 45 or older and have not been screened, talk to your doctor about which option suits you best. If the idea of a colonoscopy has kept you from acting, an at-home stool test or a blood draw removes that barrier entirely. The science has done its part. The rest is a matter of making the appointment.
