Crohn’s Disease

What is Crohn’s disease?

Crohn's disease is classified as a type of inflammatory bowel disease (IBD), a broader category of conditions characterized by chronic inflammation of the gastrointestinal tract. IBD encompasses two main disorders: Crohn's disease and ulcerative colitis. While both conditions involve intestinal inflammation, they differ in the areas affected and the nature of the inflammation. Crohn's disease can impact any part of the digestive tract from mouth to anus, often occurring in patches with healthy tissue in between. In contrast, ulcerative colitis primarily affects the colon and rectum, with continuous inflammation of the innermost lining. Understanding that Crohn's is a form of IBD helps contextualize its symptoms, diagnosis, and treatment within the broader spectrum of inflammatory intestinal conditions.

Crohn’s disease causes inflammation in the digestive tract (gut), mostly in the intestines. It is one of the two main inflammatory bowel diseases. For unknown reasons, abnormal activity in the immune system causes inflammation.

Crohn’s usually affects the area where the small intestine meets the large intestine (colon). But it can involve any part of the gut from the mouth to the anus.

Crohn’s is a chronic disease—you will have it for your lifetime. But while it cannot be cured, it can be managed.

Typically, there are periods of remission when you have no (or very few) symptoms. When symptoms act up, it’s called a flare.

Most people with Crohn’s require long-term treatment to decrease gut inflammation and keep symptoms from getting in the way of life.

Most common symptoms

Symptoms vary depending on which part of the gut is affected. Many cases of Crohn’s occur in the specific region where the small intestine meets the colon. This area is called the ileocecal region. Typical symptoms include:

• Abdominal pain (can be anywhere, but often in the right lower part of the abdomen)
• Cramping-type pain
• Diarrhea
• Fatigue
• Fever
• Weight loss without dieting
• Mass in the abdomen that you can feel with your hand

Other symptoms you may have

Depending on where in the gut Crohn’s is present, symptoms can also include:

• Pain around the anus.
• Stool coming from the vagina because of a fistula (an abnormal connecting pathway).
• Air in your urine (you may notice urine flow interrupted) or stool in your urine caused by a fistula.
• Mouth sores (ulcers).
• Severe nausea and vomiting if inflammation creates an intestinal blockage.
• Frequent bloody diarrhea.
• Headaches, blurry vision, increased eye sensitivity to light.
• Eye burning or itching.
• Back or joint pain.
• Skin sores or bumps.

What are the symptoms for Crohn’s disease in children?

It’s common for Crohn’s to start in adolescence. Occasionally, it occurs in younger children.

Symptoms are similar to what adults experience but may not be as obvious at first. You may notice unexpected weight loss or that your child is no longer growing as fast. Or their arms or legs have become thinner (called muscle wasting). If you notice these signs, call your pediatrician as soon as possible.

Causes of Crohn’s disease

Crohn’s disease is caused by a misfiring immune reaction. The prevailing theory is that in people with Crohn’s, otherwise harmless bacteria (or other microorganisms) are seen as an invader, and the immune system attacks it.

It is not really known why the immune system responds this way. The inflammatory response causes a lot of reactions in the gut. The inflammation becomes constant and it starts to damage the walls of the intestines, causing holes and thickening in different areas. This leads to pain and other symptoms.

It is also not known why people get Crohn’s. Genes may play a role. If a parent or sibling has it, you have an increased risk. Cigarette smokers are also more likely to develop Crohn’s.

How serious is Crohn’s disease?

It’s important to see a doctor to get the correct diagnosis. Symptoms of Crohn’s can mimic other issues, like an infection or other inflammatory disorders.

If your pain is severe or you have bloody stool, a mass in the abdomen that you can actually feel, or sudden blurry vision or increased sensitivity to light, go to the ER.

If you have unexplained weight loss (meaning you are not dieting), severe pain around the anus, stool coming out of the vagina or air or stool in your urine—without any of the other symptoms—call your doctor for an urgent appointment. These are signs of a possible complication, like a fistula.

Diagnosing Crohn’s disease

You should see a gastroenterologist, a doctor who specializes in the digestive system. Certain medical procedures are needed to confirm a Crohn’s diagnosis.

You will need a colonoscopy. For this test, a flexible tube with a small camera is inserted through the anus to examine the inside of the large intestine and part of the small bowel.

You may also need an upper endoscopy if your symptoms suggest that your upper digestive tract is affected. In this procedure a similar tube is inserted down your throat to examine your esophagus, stomach, and part of your intestine.

During both procedures, the doctor will biopsy (remove) small pieces of tissue for testing. Both procedures are done under anesthesia but on an outpatient basis in a surgical center or an endoscopy center.

Depending on the findings, your doctor may want to do additional tests to see how much of the gut is affected. Often some parts of the gut are affected but not others (called skip lesions).

You may need an imaging study called magnetic resonance enterography (MRE) or a CT enterography. Another option is a video capsule endoscopy. It involves swallowing a small pill camera that takes pictures of the digestive tract.

Can Crohn’s disease be cured?

Crohn’s cannot be cured but the inflammation and symptoms can usually be managed. The goal of treatment is to stop the inflammation causing Crohn’s so the gut can heal. Treatments can also keep it from getting worse. The disease will then be in remission, which means you’ll have few to no symptoms.

There are a variety of medications that can be used. The medication your doctor chooses will depend on what parts of your gut are affected as well as how you respond and tolerate side effects of different options. Depending on the medicine, you may take it orally, by injection, or intravenously in a hospital or outpatient infusion center.

Medications

Medications that are commonly used for Crohn’s are as follows (your doctor may also prescribe additional medications, especially if your colon is affected):

• Steroids (such as prednisone).
• Antibiotics (such as ciprofloxacin and metronidazole).
• Immunosuppressants (such as azathioprine or methotrexate).
• Biologicals (also immunosuppressants - such as infliximab and vedolizumab).

Once you are on medication, you should start to see an improvement in symptoms within a few days (e.g. with prednisone or methylprednisolone) to several weeks. Continue taking all medications as prescribed, even if you are feeling better.

A little less than half (about 47%) of people with CD will require surgery within 10 years of being diagnosed. However, sometimes less invasive procedures (such as draining an abscess) can be used instead of surgery.

You will need to see your gastroenterologist regularly to check how you are doing and if you need to change medications. It’s common to need to change medications to keep the disease in remission and prevent more inflammation. Sometimes a medication can stop working or become less effective over time. Medication changes, either a temporary addition of a medication or a change in medication, are common when symptoms flare.

You will also need repeat upper endoscopies and/or colonoscopies to check if your gut is healing. How frequently you need these tests vary, but typically the procedures are repeated within a year of starting a new medical treatment. Colonoscopies are also needed to watch for colon cancer, which is more common in Crohn’s patients, if the colon is affected by inflammation.