Routine screening catches most colorectal cancers. But sometimes your body sends signals that something is off before your next scheduled screening. These are the symptoms that mean you should call your doctor now, not in 3 or 10 years.
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Any single one of these, lasting more than a few weeks, is worth a doctor's visit.
Bright red blood or dark, tarry stools. Hemorrhoids are a common cause, but rectal bleeding can also indicate polyps or cancer. Don't self-diagnose this one.
Diarrhea, constipation, or a change in stool consistency that lasts more than 2 to 3 weeks. Occasional irregularity is normal. Ongoing change is not.
Losing weight without changing your diet or exercise habits. Unintentional weight loss of 10 pounds or more can be an early indicator of several cancers, including colorectal.
Cramping, bloating, or pain in your abdomen that doesn't resolve on its own within a few weeks. Especially if it's new and doesn't have an obvious cause like diet change.
Fatigue that persists even with adequate rest. Colon polyps and cancers can cause slow internal bleeding that leads to iron-deficiency anemia, which shows up as persistent tiredness.
If a FIT or Cologuard test comes back positive, a follow-up colonoscopy is required to determine the cause. A positive stool test doesn't always mean cancer, but it always means further investigation.
A screening colonoscopy is routine. You have no symptoms, and your doctor recommends it based on age and risk factors. A diagnostic colonoscopy happens because something prompted it: symptoms, a positive stool test, or abnormal imaging.
The procedure is identical. The difference is in insurance billing. Screening colonoscopies are typically covered at 100% with no copay under the ACA. Diagnostic colonoscopies may involve cost-sharing depending on your plan. This billing distinction frustrates a lot of people, especially when a screening colonoscopy gets reclassified as diagnostic because polyps were found and removed during the procedure.
Regardless of how it's billed, if you have symptoms, don't let cost concerns delay the appointment. Early detection saves lives and money. Late-stage colorectal cancer treatment can cost $100,000 or more.
The standard recommendation to start screening at age 45 applies to average-risk adults with no symptoms. If you're 30 and have rectal bleeding, or 25 with a strong family history of colorectal cancer, the age guideline doesn't protect you.
Colorectal cancer rates in adults under 50 have been rising for two decades. The American Cancer Society reported a 2% annual increase in incidence among younger adults from 1995 to 2019. If something feels wrong, bring it up with your doctor regardless of your age.
For age-specific screening recommendations, see our full colonoscopy screening guidelines by age guide. For the broader picture of why screening matters, visit the main colonoscopy screening reminder page.
Persistent changes in bowel habits (diarrhea or constipation lasting more than a few weeks), blood in stool, unexplained weight loss, ongoing abdominal pain or cramping, and fatigue that doesn't improve with rest. Any of these warrants a call to your doctor.
Yes, contact your doctor. Blood in stool can have many causes, including hemorrhoids, but it can also be a sign of polyps or colorectal cancer. Your doctor will determine whether a colonoscopy is needed based on your age, symptoms, and risk factors.
Yes. If you have symptoms like rectal bleeding, persistent bowel changes, or unexplained weight loss, your doctor may recommend a colonoscopy regardless of age. Family history of colorectal cancer or genetic syndromes like Lynch syndrome also warrant earlier screening.
A screening colonoscopy is routine, performed on people with no symptoms. A diagnostic colonoscopy is ordered because of specific symptoms or abnormal test results. The procedure is the same, but insurance coverage and billing may differ.
Don't wait. Contact your doctor within a week if symptoms persist. Most symptoms turn out to be something less serious, but colorectal cancer survival rates are significantly better when caught early. The sooner you investigate, the better the outcome.
If you're noticing changes, talk to your doctor. And whether your next screening is routine or urgent, set a reminder so the follow-up doesn't fall through the cracks.
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