Changes in Bowel or Bladder Habits

This page is for anyone who has noticed a lasting change in their bowel or bladder habits. It covers which changes to mention, common non-cancer causes, and what tests a doctor may do.

Everyone's bowel and bladder habits vary a little from day to day. A change that is new and lasts, not just a passing upset, can occasionally be a warning sign of cancer. Most such changes come from something else. But changes that last should be checked.

Watch for:

• New constipation or diarrhea that does not go away.
• Stools that look narrower than usual.
• A feeling that your bowel does not fully empty.

These changes can be a warning sign of colorectal cancer, a cancer of the colon or rectum. A growing tumor can narrow the passage stool travels through, or change how your bowel muscles work.

Watch for:

• Needing to urinate more often than usual, including at night.
• Feeling a constant urge to urinate even when the bladder is empty.
• Pain or burning when urinating.

These changes can signal bladder cancer. Blood in the urine, which can look rusty to bright red, even a small amount, deserves prompt attention on its own.

Many conditions other than cancer can cause these changes, and a doctor can sort out which. NCI notes that urinary tract infections, kidney stones and bladder stones can cause symptoms like bladder cancer does. Many bowel symptoms are also shared by other conditions. Only a doctor can tell them apart.

Your doctor asks how long the change has lasted, exactly what has changed, and whether you have noticed blood, pain, or weight loss.

• For bowel changes, a stool test that checks for hidden blood, called a fecal immunochemical test, is a common first step. A colonoscopy uses a thin, flexible tube with a camera to examine the entire colon. It gives a direct look and lets doctors remove tissue for a biopsy (a small sample for testing) if anything looks abnormal.
• For bladder changes, a urine test checks for blood or infection, and a cystoscopy, which looks inside the bladder with a thin scope, may follow if needed.

Per the National Cancer Institute, a pathology report usually reaches your doctor within 10 days of the biopsy. Your care team can tell you when to expect the call.

A normal test does not explain every symptom. If your symptoms continue after normal results, or you develop new ones, tell your doctor rather than assuming the issue has been fully explained.

Note what changed, when it started, and how it compares with your usual pattern. For bowel changes, note stool color and shape, and whether you see blood. For bladder changes, note how often you go, whether urination is painful, and whether you see blood. This detail helps your doctor decide which test to order first.

• Call your care team the same day if you see blood in your urine or your stool, or if urinating has become painful and you also feel feverish or unwell.
• Call your care team within a day or two if your bowel or bladder pattern has stayed different from your normal one and is not going away, if stools look narrower than they used to, or if new belly or pelvic pain has settled in alongside the change.

• Should this change be evaluated with tests?
• Could it be caused by something other than cancer?
• Do I need colorectal or urinary screening?
• What symptoms should prompt me to come back sooner?

• National Cancer Institute — Colon Cancer Treatment (PDQ)
• National Cancer Institute — Bladder Cancer Symptoms
• National Cancer Institute — Bladder Cancer Treatment (PDQ)
• National Cancer Institute — Pathology Reports