By Kristen Sturt
illustration of large intestine, Crohn's disease and ulcers

Medically reviewed by Jenny Blair, MD

When you have Crohn’s disease (CD), inflammation often causes ulcers to form in your digestive tract. These open sores may be mild or severe, and can lead to more serious complications, like fistulas and strictures. They’re considered a hallmark of the condition.

“We look for the presence of ulcers to help us make the diagnosis,” says David Binion, MD, a gastroenterologist and co-director of the Inflammatory Bowel Disease Center at the University of Pittsburgh Medical Center in Pennsylvania. And the larger and deeper the ulcers, he adds, the more serious the ramifications. “It’s a warning sign in terms of what’s coming down the road in years ahead.”

Where Ulcers Are Found

With CD, ulcers most often develop in the large intestine (shown in the above image) and the last third of your small intestine, known as the ileum. The earliest to appear are tiny aphthous ulcers—oval-shaped, white lesions found on the surface of the lining of the gastrointestinal (GI) tract, called the mucosa. Aphthous ulcers can grow, deepen and combine as CD progresses. Together, they may form larger stellate (star-shaped) ulcers or long lines called linear ulcers, which can give the intestinal wall a clawed appearance.

Ulcers in CD can be continuous, taking up large swaths of the mucosa. “Or, they can happen in patchy way, so that some areas are normal and there are nearby areas that are not normal,” says Ruby Greywoode, MD, a gastroenterologist and assistant professor of medicine at Rutgers Robert Wood Johnson Medical School in New Brunswick, New Jersey. In images, alternating normal and ulcerated tissue may sometimes look like a cobblestone street.

While ulcers are less common beyond the ileum and large bowel, they can occur anywhere in the GI tract, from mouth to anus. “Sometimes we will see patients with upper GI tract ulcers that involve the esophagus, the stomach or perhaps the beginning of the intestine, the duodenum,” says Dr. Binion. About 20 to 30 percent of adults with CD will develop aphthous ulcers in their mouths. Frequently called canker sores, these can result from inflammation or be a side effect of drugs used to treat the disease. (People without Crohn’s sometimes get aphthous ulcers too.)

How Crohn’s Ulcers Affect You

Though some CD patients don’t experience any symptoms, according to Dr. Binion, the large majority will; they’re often the first recognizable indication of disease. As a result of inflammation and ulceration, many people will feel pain or see blood in their stool, says Dr. Greywoode. Weight loss and diarrhea are common symptoms, as well.

Crohn’s ulcers can also lead to severe complications, like strictures. “Ulcers, particularly the larger ulcers, will go through repeated cycles of inflammation, damage and healing,” says Binion, “and the healing will oftentimes lead to scar formation.” That scarring can cause a narrowing of the intestine—a stricture—which hinders food from passing through. This may lead to blockages, stricturing and/or severe inflammation can also cause life-threatening perforation of the bowel. A perforated bowel requires surgery, Binion adds, though, “we try very hard to help our patients before they get to that point.”

Fistulas are another potentially serious complication, often developing next to strictures. They occur when ulcers break through intestinal walls, forming abnormal passageways to another part of the intestine or another part of the body, like the bladder. “It’s the body’s attempt to create a new opening to bypass the area of damage,” says Binion. About 30 percent of CD patients will develop fistulas, which can become infected and may require medication or surgery.

Treatments for Ulcers and Crohn's, patient's hand in hospital bed

How to Treat and Prevent Ulcers

There is no cure for CD, and in the past, treatment focused on alleviating symptoms. Now, says Binion, it’s believed that mucosal healing, defined by the absence of ulcers, is crucial to disease management and overall quality of life. “When patients are able to heal ulcers, that actually has very, very important prognostic implications they will be well,” he explains.

To achieve this, healthcare providers will very likely prescribe medications, the type of which depend on the location and severity of your CD. Common drugs include corticosteroids, which lessen inflammation, and immunosuppressants, which help control the immune system’s ability to trigger inflammation. Crohn’s patients are often warned against using non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, however, as research suggests they may aggravate the disease.

Surgery may be necessary if your CD doesn’t respond well to medical therapy. One common procedure to alleviate ulcers and associated complications is a resection, which removes a damaged part of the intestine and connects the healthy ends.

Mucosal healing and remission in general can be aided by a healthy lifestyle, including eating a nutritious diet, getting plenty of physical activity and avoiding smoking. Tobacco use, says Greywoode, “puts you at increased risk of having more severe disease—and having complications related to your disease.”

Also crucial: sticking to your treatment plan, even if you’re in remission and feel fine. This may include staying on medications and attending regular exams. “Since ulcerative colitis is a chronic disease we cannot cure as of yet,” Greywoode says, “the best strategy we recommend is to remain on treatment even if you’re in remission to prevent disease recurrence and further complications.”

Jenny Blair is a writer and journalist covering science, medicine, and the humanities. She earned her MD at Yale University, then completed a residency in emergency medicine at the University of Chicago. After several years in practice, she transitioned to working with words and ideas full-time. Jenny has contributed to Discover, New Scientist, Washington Spectator, and Medtech Insight, among other publications. She lives in New York City.

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