What should you know about persistent change in bowel habits?

Changes may include constipation, diarrhoea, alternating between the two, narrower stools, more frequent bowel movements or a feeling that the bowel has not emptied. Food, medicines, infection, inflammation and changes in the bowel can all affect bowel movements. A bowel habit change is a common presentation of bowel cancer, but the symptom alone does not establish a diagnosis. Rectal cancer can also present with altered bowel movements, particularly when the change is new and does not settle.

Tell a clinician when the change began, whether it is getting worse, and whether you have noticed blood, abdominal discomfort, weight change, tiredness or a change in appetite. These details help guide examination and any tests.

Arrange an appointment if the new pattern persists, returns repeatedly or interferes with daily life. Keep a brief record of stool frequency, consistency, colour, bleeding, pain and medicines. Drink normally and avoid taking laxatives or anti-diarrhoeal medicines repeatedly without advice, because they may be unsuitable for the underlying cause. A clinician may examine your abdomen and discuss stool tests, blood tests or further bowel assessment based on your symptoms.

Seek urgent medical help for heavy or ongoing rectal bleeding, black stools, severe or worsening abdominal pain, repeated vomiting, a swollen abdomen, faintness, confusion, or inability to pass stool and gas. Contact a clinician promptly if bowel changes occur with unexplained weight loss, marked weakness, fever or persistent blood in the stool.

Ask what causes are being considered, which warning signs matter in your situation, whether your medicines or diet could contribute, and which tests would clarify the change. Ask how to manage constipation or diarrhoea safely while assessment is underway.