WHAT DOES REMISSION MEAN IN IBD?

Since there isn't a cure for IBD yet (notice we said yet, because a lot of research is focused in that direction), what we try to do is get patients into "remission". But remission is a tricky word that means different things medically, whether we're talking about IBD, cancer or other diseases. 

Clinical remission is when a patient no longer has any gastrointestinal symptoms of the disease. In IBD (Crohn's disease or ulcerative colitis), that's no diarrhea, no blood, no abdominal pain, and no rectal problems. Basically, the person in clinical remission feels well and there are no physical signs, like blood or a fistula . 

Biomarker remission is a term that's occasionally used in IBD. It's when a patient is in a clinical remission and the standard blood and stool tests are also normal. That usually includes blood counts, sedimentation rate (ESR), C-reactive protein (CRP) and stool or fecal calprotectin (FC). But that's a bit of a problem, since what's normal at one laboratory can be considered abnormal from another lab—so the doctor has to use the "normal values" from the specific laboratory where the test was done.

Deep remission is a new term that also includes the intestinal tract-so that it shows no disease. Deep remission usually refers to the intestine looking normal on colonoscopy and / or capsule endoscopy, with no active disease seen. That's become an important goal, and far more important, because deep remission translates to patients having less chance or surgery or hospitalization.     

Histological remission also means that all the biopsies taken at a colonoscopy are normal.

Transmural remission means that the intestine in Crohn's disease shows no abnormality on meaningful x-ray procedures (CT, MRE, certain ultrasounds called SICUS). Since Crohn's disease can affect deeper layers of the intestine, this may prove to be quite important. This is not as important in ulcerative colitis, which is considered a disease of the inner layers of the intestine that can be seen and biopsied at the time of a colonoscopy. 

While histological and transmural remissions are "deeper" remissions, only a few studies have been done using these tools. But those studies do show that patients with these types of remissions do show even lower risk of later surgery or complications.  

Complete remission is a term that is used for cancer patients, meaning there is no evidence of disease. The cancer seems to be gone. It is not a term that is used with IBD because it would take a combination of all of the types of remission (and all the tests) to say that there is no evidence of disease. 

Notice that being in remission doesn't mean being off medication or treatment. IBD patients usually require continued treatment in order to enter remission and to maintain a long-term or sustained remission.  

Different Types of Remissions  

• Clinical Remission Patient feels well, and no clinical signs
• Biomarker Remission Clinical remission + blood and stool tests are normal
• Deep Remission Above + intestine looks normal
• Histological Remission All above + biopsies are normal 
• Transmural Remission Deep Remission + no evidence of disease on CT, MRI or SICUS
• Complete Remission Histological + Transmural Remission
• Sustained Remission Long-term remission (the length is not defined, usually 1 year +)