Changes in Bowel or Bladder Habits

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, or a feeling that your bowel does not fully empty, are both worth noting. 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 or less often than usual, trouble starting or stopping the stream, or pain when urinating. These changes can signal bladder cancer or, in men, an enlarged or cancerous prostate. Blood in the urine, even a small amount, deserves prompt attention on its own.

Diet changes, a stomach bug, or stress can all cause temporary bowel changes. Hemorrhoids commonly cause changes in bowel habits and sometimes light bleeding. An enlarged prostate, common as men get older, is a frequent non-cancer cause of urinary changes. Urinary tract infections cause many of the same bladder symptoms as more serious problems, and they usually clear up quickly with treatment.

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 — a thin, flexible tube with a camera that examines the entire colon — gives a direct look and lets doctors remove tissue for a biopsy 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 clear stool test does not rule out every colorectal problem, since some tumors bleed only occasionally. A urine test that shows no infection does not explain every bladder symptom either. If your symptoms continue after normal results, or you develop new ones, follow up 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 for more than a couple of weeks, 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 Treatment (PDQ)
• National Cancer Institute — Pathology Reports