Please verify your email address to receive email notifications.

Enter your email address

We have sent you a verification email. Please check your inbox and spam folder.

Unable to send verification, please refresh and try again later.

  • Q&A with Australian Health Practitioners

    Can a blood test and stool test alone rule out IBD?

    I have crohn's and my 21 year old niece has been told she has irritable bowel disease. I am concerned that she wasn't given a colonoscopy. Could the blood test and stool test alone rule out inflammatory bowel disease?
  • Find a professional to answer your question

  • 6


    A/Prof Greg Moore


    Greg Moore is a Gastroenterologist specialising in Inflammatory Bowel Diseases (IBD), Crohn's Disease and Ulcerative Colitis. He is Head of IBD at Monash Medical Centre … View Profile

    The diagnosis of Crohn's disease is typically made on the basis of symptoms, blood tests, stool tests and colonoscopy +/- gastroscopy especially in younger patients and some times diagnostic imaging procedures (CT or MRI scanning). 
    Blood tests can show signs of inflammation (raised white blood cells, inflammatory markers), anaemia or iron deficiency or other vitamin deficiencies associated with Crohn's disease (eg. B12 deficiency).
    Endoscopy (gastroscopy and colonoscopy) allow visualisation of the bowel wall and taking biopsies to check for microscopic inflammation)
    Stool testing can pick up whether there are white blood cells, red blood cells in the stool which suggests an inflammatory process but could also mean infection. The culture of stool is used to find infective causes but is not 100% accurate.
    A newer stool test called faecal calprotectin is very good at distinguishing inflammatory (IBD, infections) from non-inflammatory (eg irritable bowel syndrome).
    Irritable Bowel Syndrome is common and affects up to 20% of young women. There is no specific diagnostic test that diagnoses IBS, but rather the diagnosis is made on a constellation of symptoms and the absence of warning signs and symptoms. Sometimes other tests such as endoscopy are used to rule out IBD.
    Depending on whether there are no warning symptoms and the particular types of blood and stool tests performed, it may be reasonable to not perform colonoscopy. Symptoms of diarrhoea with blood require colonoscopy. Significant weight loss would also make endoscopy indicated.
    Without specific knowlege of the clinical history and particular tests performed, it is not possible to be more definitive as to the appropriateness of not performing colonoscopy.

answer this question

You must be a Health Professional to answer this question. Log in or Sign up .

You may also like these related questions

Ask a health question
Community Contributor

Empowering Australians to make better health choices