Does a blood test treat Crohn's disease?

Blood tests may look for signs of inflammation, anaemia, dehydration, infection or reduced nutrition. They can help a clinician understand how active Crohn's disease may be and whether medicine is affecting the liver, kidneys or blood cells. Blood results are only one part of assessment: symptoms, stool tests, scans and endoscopy may also be used when appropriate. A change in a marker does not by itself prove that the intestine has healed or that treatment has failed.

Treatment is selected according to the part of the digestive tract involved, symptoms, inflammation and previous response. Options may include medicines that calm inflammation, nutritional support or surgery for certain complications. Blood testing helps make care safer and more tailored, but drawing blood does not remove intestinal inflammation.

Attend the blood-test appointment and bring a list of medicines, vitamins and recent symptoms. Tell your care team about fever, new abdominal pain, diarrhoea, blood in the stool, reduced eating or unintended weight loss. Continue prescribed treatment unless your gastroenterology team changes it. Ask when results will be reviewed and whether a stool test or other investigation is needed to understand disease activity.

Get urgent medical advice for severe or increasing abdominal pain, repeated vomiting, a swollen abdomen, persistent fever, heavy rectal bleeding or inability to keep fluids down. Go to emergency care for collapse, severe weakness, confusion or signs of serious dehydration. Do not wait for a routine blood-test result when these symptoms are present.

Ask which results reflect inflammation, whether you are anaemic or dehydrated, how medicine monitoring will work, and what symptoms should trigger contact before your next appointment.