What Is Mucosal Healing in IBD?

Healing the intestinal lining can slow disease progression

In This Article

The inflammatory bowel diseases (IBD) are chronic conditions, which means that they go through periods of active disease (flare-ups) and remission (loosely defined as periods of little or no disease activity). Crohn’s disease and ulcerative colitis are two IBDs that can cause ulcerations in the digestive tract.

These ulcers can affect several layers of the walls of the small and large intestine, especially with Crohn’s disease. The innermost layer of the bowel is called the mucosal layer. One of the latest benchmarks for treating IBD is having the ulcers in the mucosal layer heal, which is called mucosal healing.

Remission in IBD

In order to understand why mucosal healing is important, it is necessary to review types of remission, how they're defined, and why being in remission doesn’t always mean that the disease is being treated effectively. The idea of remission has been difficult to define for both gastroenterologists and people living with Crohn’s disease and ulcerative colitis.

For many who live with IBD, remission means that there are few or no symptoms, but this does not always mean that the disease is not still causing inflammation. It’s possible to have no symptoms but still have disease activity (such as inflammation), or to have lab results indicate the disease is still active. For this reason, several different forms of remission have now been defined, including:

  • Biochemical Remission. This is when blood and stool tests don’t show any of the markers that are typically present when IBD is active.
  • Clinical remission. This is what most people think of when they think of remission—this is when there are few or no symptoms of the disease.
  • Endoscopic remission. During an endoscopic procedure (such as a colonoscopy) the gastroenterologist can see no disease activity and any biopsies taken also show no disease. 
  • Histologic remission. When there are few to no symptoms (clinical remission) and there is also no disease activity seen during an endoscopy or in biopsies.
  • Surgical remission. After a surgical procedure (such as ileostomy, j-pouch surgery, or resection), there are few to no symptoms and also little to no disease activity.

Importance of Mucosal Healing

IBD experts are currently looking at mucosal healing as the biggest factor that is the most important to achieving a better long-term outcome.

Mucosal healing means that disease activity is not seen during a colonoscopy or another procedure that looks at the lining of the digestive tract—this means that histological remission is also present.

There could still be scar tissue in the small and large intestine from where the ulcers healed but the inflammation is gone. There is no singular definition yet, but gastroenterologists continue to use their knowledge and experience to make decisions about mucosal healing and what it means.

The various medications used to treat IBD are associated with different rates of mucosal healing. While there have been studies that show how effective a medication is for a group participating in a clinical trial, mucosal healing is still an individual process.

One of the treatment hurdles with IBD is how complicated these diseases are. While mucosal healing is especially important for IBD, they are also difficult to predict. A gastroenterologist is the best resource for helping to determine what medication might work best for a particular patient.

While still taking the complicated and individualized nature of treating IBD into account, mucosal healing is starting to be better understood and more achievable. In fact, the Food and Drug Administration (FDA) includes mucosal healing as a treatment goal for new medications being studied as a treatment for ulcerative colitis. The FDA acknowledges that this is challenging to define because the tools used in clinical trials that rate a participant’s response to treatment are imperfect.

However, it’s still recommended that the rating systems used now are continued to be employed until a new one is developed. Furthermore, some researchers question how well the rating systems used in clinical trials can really translate to real-life experiences.

Mucosal Healing and Disease Course

Some studies have shown that when there is mucosal healing, there is a decrease in certain risks associated with IBD. For ulcerative colitis, this could mean lowering the risk of having a colectomy or of developing colon cancer. For Crohn’s disease, achieving mucosal healing could mean a decreased risk of surgery and of needing to take steroids for treatment.

In the exam room, this means that treatment goals should include not only reducing symptoms, but also the actual healing of the intestinal mucosa. This is called "treat-to-target." How much the mucosa needs to be healed in order to gain certain benefits, and for how long, is still being studied.

At this stage, the finer points are being defined but it’s generally agreed that mucosal healing is a benchmark for treatment and could lead to a less aggressive disease course.

Drawbacks

Mucosal healing can alter disease course and ultimately benefit patients. However, getting to that point is a challenge. In the clinical trials done so far, treating-to-target involves a pretty intense regimen that includes having endoscopies (such as colonoscopies) more frequently and ramping up treatments. Not only does this mean that patients need to see their doctors more often and make treatment adjustments more frequently, but it also means that there is more cost involved.

Something that works in a clinical trial is usually more difficult for patients and gastroenterologists to achieve with more limited means. Research is being done to find non-invasive ways to assess mucosal healing, but even those methods (such as stool testing) have their own barriers to being used more frequently.

A Word From Verywell

Traditionally, treating IBD has meant reducing symptoms. Now, it's understood that healing the lining of the digestive tract has a greater long-term impact on disease course. It’s not clear yet exactly how mucosal healing should be determined—more research is being done to develop a clear set of tools for mucosal healing. In some cases, this means using a treat-to-target approach to IBD. As more research is done, the way the disease is treated will continue to be updated. 

Was this page helpful?

Article Sources

  • Colombel JF, Panaccione R, Bossuyt P, Lukas M, Baert F, Vaňásek T, et al. Effect of tight control management on Crohn's disease (CALM): a multicentre, randomised, controlled phase 3 trial. Lancet. 390:2779-2789. DOI: 10.1016/S0140-6736(17)32641-7

  • Dave M, Loftus EV. Mucosal healing in inflammatory bowel disease-a true paradigm of success? Gastroenterol Hepatol (N Y). 8:29-38.

  • Lopez-Sanroman A. The Concept of Mucosal Healing in Ulcerative Colitis: Time and Reasons for a Reappraisal. Journal of Crohn's and Colitis. 10:3-4. DOI: 10.1093/ecco-jcc/jjv183

  • Römkens TE, Kampschreur MT, Drenth JP, Van oijen MG, De jong DJ. High mucosal healing rates in 5-ASA-treated ulcerative colitis patients: results of a meta-analysis of clinical trials. Inflamm Bowel Dis. 18:2190-2198. DOI: 10.1002/ibd.22939