How common is blood in stool in Crohn's disease?

Crohn's disease involves inflammation in the digestive tract. Inflamed or ulcerated tissue can bleed, particularly when disease affects the colon or rectum. Blood may appear with loose stools, mucus, urgency, cramping, fatigue, reduced appetite, or weight change. The amount and appearance of blood do not establish the cause, because infections, haemorrhoids and other conditions may produce similar bleeding.

Contact your clinician if you have new bleeding, worsening bowel symptoms, or known Crohn's disease with a change from your usual pattern. Keep track of stool frequency, colour, pain, fever, appetite and fluid intake. Your care team may consider examination, blood or stool tests, and assessment of whether intestinal inflammation is active. Continue your treatment plan unless the prescriber advises a change.

Get urgent medical care for heavy bleeding, black tar-like stool, fainting, severe weakness, persistent vomiting, severe belly pain, a swollen abdomen, or signs of dehydration such as very little urine and inability to keep fluids down. These symptoms require prompt assessment regardless of the underlying cause.

You may ask whether the bleeding could reflect active inflammation, whether your current medicines need review, what monitoring is appropriate, and which warning signs merit same-day help. Tell the clinician about recent travel, antibiotic use, sick contacts and medicines that can irritate the digestive tract.