STOOL (FECAL) TESTS IN IBD

No one wants to look at their bowel movements, let alone collect them. It's disgusting, embarrassing, humiliating—but very important, especially if you (or your child) has Crohn's disease, ulcerative colitis (UC) or any of the other inflammatory bowel disease (IBD). 

Sometimes, it's obvious that's there's blood or mucus in the bowel movement (stool, feces, poop, or whatever term you want to apply). Other times, it's necessary to scrape a small amount of the feces onto a card so that it can be tested. And other times, cups and containers are needed to run an entire battery of tests. 

The Individual Tests

Blood or Occult Blood: A number of different tests look for traces of blood in the stool. They actually look for the iron or particular protein that's in the blood. So patients shouldn't be taking iron or eating large amounts of rare meat, because some of the tests will falsely indicate that blood is present (and of course, it shouldn't be). For the same reason, this test should not be done on girls or women in the midst of their menstrual flow. 

Sometimes, the test for blood is done in the doctor's office after the doctor uses a lubricated, gloved finger to examine the rectum. He or she will be feeling the tissue inside. Often there is fecal residue from the exam that can be tested for blood.

White Blood Cells can be an indicator of inflammation or infection, so a small amount of stool can be smeared on a slide and placed under the microscope. That fecal smear can also be used to look for particular types of white cells, usually eosinophils to look for the possibility of food allergies that may be causing an intestinal reaction. The smear can also reveal the presence of yeast. But you should know that certain yeast normally live in the large intestine (and some can be given as a probiotic) while another, C. albicans, is usually considered as an infection that should be treated. 

Calprotectin is a relatively new test for a protein that's found in the white cells–and it's easier to measure even when there's a small stool specimen (we get a number rather than a just being told none, few or lots of white cells are seen). Calprotectin is increased in inflammation and infection (it's usually much higher in active IBD than infection, and often higher when the disease is active in the large intestine compared to the small intestine). So the test is used to determine IBD activity and severity, and sometimes it's used to indicate whether further testing (a MRI or colonoscopy) is necessary.

Lactoferrin is similar to calprotectin in evaluating inflammation and infection as another cell protein that often is found more with small intestinal disease. Other stool tests are being recommended to test for allergies, food sensitivities and other disorders. Since research hasn't shown their accuracy or meaning yet, they are not widely accepted by the medical community.