3 Bowel Changes That Deserve a Medical Check

Nearly 159,000 Americans are projected to receive a colorectal cancer diagnosis in 2026—about 440 diagnoses each day, according to the American Cancer Society. The disease is also increasing in adults under 65, so changes in your bathroom routine deserve attention rather than dismissal.

Why tracking bowel health matters

Colorectal cancer can begin as polyps that cause no symptoms. As a growth enlarges, it may interfere with the passage of stool or irritate the bowel. That is why a new, persistent change can matter even when you otherwise feel well.

The increase among younger adults is especially relevant: from 2013 through 2022, incidence rose about 3% annually among adults ages 20 to 49 and 0.4% annually among those ages 50 to 64. Distal colon and rectal cancers account for much of that rise. Colorectal cancer is now the leading cancer killer among adults younger than 50, according to the American Cancer Society.

For adults at average risk, screening starts at age 45. The 2026 ACS update includes blood-based screening and newer at-home multitarget stool DNA and RNA tests, including Cologuard and ColoSense. Symptoms still require medical evaluation; a screening test is not a substitute for discussing a problem with a clinician.

1. A recurring sense that you are not finished

Tenesmus is the repeated urge to have a bowel movement even after you have gone. You may return to the bathroom several times, pass very little, or feel pressure low in the abdomen. Irritation, inflammation, or a blockage can cause it; a growth in the rectum or lower colon is one possible explanation.

Do not diagnose yourself from this symptom alone. If the sensation keeps returning, arrange an appointment with a primary care clinician or gastroenterologist.

2. Blood on the paper, in the bowl, or mixed with stool

Bright red blood often comes from the lower colon or rectum and may appear on toilet paper or in the bowl. Hemorrhoids and anal fissures are common causes, but new rectal bleeding still deserves assessment rather than an assumption that it is harmless.

Very dark, sticky, or tar-like stool can indicate bleeding higher in the digestive tract, including the upper gastrointestinal system. Contact a healthcare professional promptly, especially when bleeding returns or occurs alongside a bowel-habit change, weakness, or abdominal symptoms.

3. Bowel habits that stay different

A brief bout of constipation or diarrhea can follow stress, food changes, or a minor infection. The concern is a shift that persists: going much more often than usual, developing stubborn constipation, or having diarrhea that does not settle.

Pay attention to shape as well as frequency. Stool that repeatedly becomes unusually narrow—often described as pencil-thin—may reflect narrowing inside the colon from a polyp, tumor, or another condition. Record when the change began and tell your clinician what you have noticed.

Other symptoms that belong on your radar

Bowel changes are not the only clues. Colorectal cancer can also produce symptoms that seem unrelated to digestion, so patterns matter.

• Unplanned weight loss: Losing weight without changing your eating or activity habits needs an explanation.
• Ongoing abdominal discomfort: Repeated cramps, gas pain, or general abdominal pain should not be treated as normal if it continues.
• Fatigue or weakness: Slow blood loss can cause iron-deficiency anemia, leading to marked tiredness, pale skin, or shortness of breath.

These symptoms have many possible causes, including irritable bowel syndrome, Crohn’s disease, and food intolerances. Their presence does not prove cancer, but persistence or a combination of symptoms warrants a medical review.

What to do when a warning sign appears

Do not panic, but do not wait indefinitely. Note the symptom, how often it occurs, its duration, and any associated bleeding, pain, weight change, or fatigue. Then schedule an appointment with your primary care clinician or a gastroenterologist.

The clinician may review your history, examine you, and order testing. A colonoscopy allows direct inspection of the colon and rectum and can remove suspicious polyps during the procedure. At-home or blood-based screening can improve participation, but any positive non-colonoscopy test requires a timely follow-up colonoscopy, preferably within six months, according to the CA: A Cancer Journal for Clinicians.

Questions people commonly ask

Can younger adults get colorectal cancer? Yes. Risk generally increases with age, but incidence is rising among adults under 65, and symptoms should be assessed at any age.

When should average-risk screening begin? The current ACS recommendation is age 45. A family history or other elevated-risk factor may lead a clinician to recommend an earlier plan.

Does diet affect risk? Diets high in red meat, such as beef and lamb, and processed meat, including hot dogs and bacon, are linked with higher risk. Fruits, vegetables, and whole grains supply fiber that supports digestive health. Diet is only one factor, so it does not replace screening.

Are at-home tests enough after a positive result? No. A positive stool or other non-colonoscopy screening result needs follow-up colonoscopy within a reasonable timeframe, preferably within six months.