For decades, the advice was simple. Turn 50, get a colonoscopy. In 2021 that changed. The US Preventive Services Task Force1, the independent panel whose recommendations shape what insurers cover, lowered the starting age for average-risk adults to 45. Screening is recommended through age 75, with decisions after that made individually.
Five years later, plenty of people in their late forties still think they have time. The data says otherwise.
Why the age dropped
Colorectal cancer rates have been falling in older Americans for years, largely because screening finds and removes precancerous polyps before they turn into cancer. In younger adults, the trend has gone the other way.
The American Cancer Society's 2023 colorectal cancer statistics report2 found that the proportion of cases diagnosed in people younger than 55 rose from about 11 percent in 1995 to about 20 percent in 2019. Diagnoses are also shifting toward more advanced stages. Researchers do not yet have a full explanation. Diet, obesity, physical inactivity, antibiotic exposure and changes in the gut microbiome are all being studied, but no single cause has emerged.
What is clear is that a cancer that once seemed like a concern for retirees is increasingly a concern for people still raising kids and building careers.
The proportion of cases diagnosed in people younger than 55 nearly doubled in a generation.
View the data
| Year | Share under 55 |
|---|---|
| 1995 | About 11% |
| 2019 | About 20% |
Source: American Cancer Society, Colorectal Cancer Statistics, 2023
Your options
Colonoscopy is the best known test, but it is not the only one recommended. The Task Force and the Centers for Disease Control and Prevention3 list several approaches.
Colonoscopy, every 10 years for people with normal results, lets a gastroenterologist see the entire colon and remove polyps during the same procedure. It requires bowel preparation the day before and sedation, which means a day off and a ride home.
The fecal immunochemical test, or FIT, is done at home every year. It detects hidden blood in a stool sample. There is no prep and no time off.
The stool DNA test with FIT, done every one to three years, looks for both blood and altered DNA shed by cancers and some advanced polyps. It is more sensitive than FIT alone but also produces more false positives.
CT colonography, a specialized scan, is another option every five years, as is flexible sigmoidoscopy, which examines the lower part of the colon.
The stool tests come with an important rule. A positive result is not the end of the process. It means a follow-up colonoscopy is needed, and studies consistently find that a meaningful number of people never complete that step. A stool test is only as good as the follow-through.
Who should start earlier
The age 45 recommendation is for people at average risk. Some people need to start sooner or screen more often. That includes anyone with a first-degree relative, meaning a parent, sibling or child, who had colorectal cancer or advanced polyps, especially if they were diagnosed young. A common approach is to begin at 40, or 10 years before the age at which the relative was diagnosed, whichever comes first.
People with inflammatory bowel disease, a personal history of polyps, or known hereditary syndromes such as Lynch syndrome follow separate schedules set with their specialists.
Symptoms are not screening
Screening is for people without symptoms. If you have rectal bleeding, a persistent change in bowel habits, unexplained iron deficiency anemia, or unexplained weight loss, you need a diagnostic evaluation, not a screening test, regardless of your age. One of the troubling patterns in early-onset colorectal cancer is that younger patients and their clinicians sometimes attribute bleeding to hemorrhoids and wait. Bleeding should be checked.
Cost and coverage
Under federal rules, most private insurance plans cover recommended preventive screenings without cost sharing, and the Task Force recommendation for ages 45 to 49 brought those years under that umbrella. Billing can still get complicated, particularly when a polyp is removed during a screening colonoscopy or when a colonoscopy follows a positive stool test. It is worth calling your insurer before the procedure to ask how each scenario is billed.
The best test is the one that gets done
Gastroenterologists have a saying that the best screening test is the one the patient actually completes. Someone who will never schedule a colonoscopy but will mail back a FIT kit every year is far better protected than someone who keeps postponing the procedure they intend to have.
If you are 45 or older and have never been screened, the practical move is to pick a method at your next visit rather than at some future one. Bring two facts with you, whether a parent or sibling has had colorectal cancer or advanced polyps, and whether you could realistically take a day off for a colonoscopy this year. Those two answers decide most of the rest. One more detail people miss is that a positive stool test is not the end of screening. It is the start of a follow-up colonoscopy, and the protection only holds if that second step happens.
