Blood test to confirm IBD vs IBS: Why don't doctors use it?

I recently learned there is a blood test that confirms whether a patient has IBS or one of the inflammatory bowel diseases such as Chron's disease, Ulcerative Colitis, etc. Why don't more doctors utilize this test to avoid misdiagnosing patients? Is it possible that medical insurance plans discourage testing? What's really going on?

[lagoya]

very true comment and i suppose some docs just go on symptoms and how well they know their patient.if there is no red flags signs as in weight loss [severe and unintentional} and bleeding.some docs just dont do it.then u would have some people in the bracket who suffer from anxiety and this can effect the bowels and it all depends how personal a doctor is.they should also test for coliac disease and do a full thyroid panel before saying it is ibs and in chronic cases a colonoscopy should be performed.
interestingly new research is being studied that there is low grade inflamation (inflammation) in ibs.
but i agree the blood test should be performed not once but at different interivals as both ibd and coilitis can go into remission all by itself.

have u now being diagonsed with ibd after being told u had ibs

[jessie1980]

Do you know what the blood test is called or have more info on it? Also, do you know how the test works? Does it determine that you have IBD (ruling out IBS) or the other way around or one or the other? I've never heard of a blood test for IBD (would sure beat a colonoscopy and biopsy!)

[lagoya]

the blood test looks for inflamation (inflammation) markers and should include full cbc count white cell count {wbc} and red cell count {rbc} .a high wbc may show there is inflamation (inflammation) and a low rbc may mean there is bleeding.
also a liver panel should be run LFT to see if any malnutrition in the gastro tract because of lack of absorbion.
an electrolyte panel is also done to check sodium chloride potassium ans carbon d in the body as these may be lost with chronic diarrhea.

if the above bloods are not normal a biospy is generally taken to diagnose ibd/chrons etc so u still have to have the colonoscopy if there is inflamation (inflammation)

[jessie1980]

Thanks for the information Lagoya, so you're saying that the blood tests would more rule out IBD and indicate that IBS is the issue, right? I guess that makes sense.