How Doctors Are Monitoring Inflammation from IBD

By Dr. Peter Higgins

You know about the laundry list of complications that may arise with inflammatory bowel disease (IBD), including structural damage to the intestines. And you know about different strategies and lifestyle techniques to help you cope with your condition. And of course you know that seeing a doctor is a big part of actively monitoring your IBD.

But what is it – exactly – that your healthcare team is monitoring? When they take a blood test, what are they looking for? When they request a stool sample, what are they looking for? When they do a computerized tomography (CT) scan or colonoscopy, what are they looking for?

C-Reactive Protein (CRP)

When your healthcare team takes a blood test, they may be monitoring your C-reactive protein – or CRP – levels. CRP is released by the liver when inflammation is present in the body. It’s like a thermometer for inflammation – when CRP is low, inflammation is well-controlled; when CRP is high, inflammation is active (and therefore something may be wrong).

Because monitoring CRP is less invasive than a scope and less expensive than a scan, it’s commonly used to measure the severity of an IBD flare and/or the success of treatment. It can also be used to gauge whether or not inflammation is returning when therapy has been tapered or suspended.

One drawback to relying on CRP is that it’s not exclusively associated with inflammation of the GI tract. This means joint inflammation or an open sore, or even a tooth infection might contribute to a higher CRP level. Other challenges include its variability amongst individuals – some (about 20% of) people simply don’t make much CRP unless they are very, very sick; for these patients, a normal CRP is not very informative. In patients who know they increase their CRP during a flare, it can be very helpful. That’s why it’s important for patients to understand if they are CRP makers – both during a flare, and during periods of remission.

Calprotectin

When your healthcare team requests a stool sample, they may be interested in evaluating its calprotectin content. Calprotectin is a major protein found in inflammatory cells in both blood and stool. During periods of GI inflammation, the stool will contain higher than normal levels of calprotectin. These levels will be even higher when there’s visible ulceration within the GI tract. That’s why stool samples are helpful in assessing one’s IBD status (high calprotectin = active disease; low calprotectin = stable disease).

One major advantage of stool samples (over blood tests) is that they are more localized. Whereas blood passes through virtually all parts of your body, your stool passes through your intestines only. This means your stool specifically reflects what’s going on in your GI tract – and this makes it an especially useful substance for monitoring IBD.

Endoscopy and scans

Sometimes, if you are experiencing signs and symptoms that suggest active inflammation or structural damage (blockages, abscesses and/or fistulas) your doctor will want more than a blood or stool sample. He/she will want to actually see the tissue in order to determine the nature of the problem – its location and severity. If this is the case, your doctor may arrange for an endoscopy or a CT scan.

In an endoscopy, your doctor inserts a thin, flexible tube – attached to a light and tiny camera – into your GI tract. This device captures images of the intestinal lining and allows the doctor to take samples (or biopsies) of the tissue for evaluation under a microscope. Endoscopies look at one part of your GI tract at a time, and may not view all of your GI tract.

Colonoscopy and sigmoidoscopy are two common types of endoscopy used for monitoring inflammation in IBD. Colonoscopy can be used to look at the whole colon and lower part of the small intestine whereas as sigmoidoscopy shows only the rectum and lower part of the colon. Upper endoscopy views the esophagus, stomach, and the first part of the small intestine (the duodenum). Some people will have inflammation in the small intestine between the duodenum and the colon. This region makes up about 18 feet of small intestine. If your doctor needs to see the lining of the small intestine, a balloon endoscopy or capsule endoscopy will be used. Your doctor will select the most appropriate option for you, based on your symptoms and disease history.

While endoscopy sees the inside of the intestines, a CT or MR scan takes images from several different angles to create a complete picture of your GI tract. This allows your doctor to see the intestines, as well as areas outside of the intestines, and then visually identify areas that look actively inflamed or strictured, and to see problems like fistulas or abscesses.

And while prepping your body for these sorts of procedures can be uncomfortable and unpleasant, they are invaluable screening methods that will allow your doctor to better understand your disease course, and thus provide you with the best possible care.

Monitor you doctor’s monitoring… and monitor some more

While it may be up to your doctor to select the best monitoring methods for your IBD, this doesn’t mean you should sit back and play a spectator role. Ask what types of biological indicators your doctor is screening for. It is important to know at any point in time whether you have active inflammation. Just like a diabetic needs to monitor the level of sugar in their blood, you should monitor the amount of inflammation in your intestines.

Patients who have been doing very well (in remission) may only need to measure their inflammation once a year. Patients who have had a flare in the past year, or have had complicated disease should be monitored more often, usually about every 3 months. Any time you start a new therapy, you should measure your level of inflammation before you start, and after the therapy should be working (8-16 weeks). An effective therapy should make the inflammation go away. Go over your test results with a member of your healthcare team and have them explain – at a basic level – what it all means. Inquire about self-monitoring practices and any available resources that might help you track your condition.

Now learn more about fecal calprotectin tests for Crohn's or colitis

And remember: you are your own best monitoring tool, so trust your gut (pardon the pun) and when you’re feeling sick or strange, consult a healthcare professional. It could be a good time to measure your level of inflammation.

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