Crohn’s Disease

Crohn’s disease is a form of inflammatory bowel disease that is a lifelong condition. The immune system causes ongoing inflammation in the digestive tract. It can affect different parts of the digestive tract, but most often affects the beginning of the large intestine and the end of the small intestine. Crohn’s disease is becoming more common, with about 1 million people in the United States living with the condition.⁴

Symptoms can differ from person to person and may include stomach pain, diarrhea, fatigue, weight loss, and reduced appetite. Crohn’s disease often follows a flare and remission pattern, with periods of active disease followed by times of fewer or no symptoms. There is no cure, but treatment focuses on controlling inflammation, relieving symptoms and preventing complications to help people maintain a good quality of life.

The type of Crohn’s disease depends on which part of the gastrointestinal tract is affected. Knowing the type can help explain symptoms, possible complications, and how the disease is managed. The types of Crohn’s disease include:

• Ileocolitis: The most common type. It causes inflammation in part of the large intestine and in the lower part of the small intestine. Symptoms may include stomach pain or cramping, diarrhea, and weight loss.
• Gastroduodenal: Inflammation in the top of the small intestine and in the stomach. Symptoms include vomiting, nausea, weight loss and loss of appetite.
• Ileitis: Causes inflammation in the small intestine. Symptoms may include abdominal pain, cramping, diarrhea and weight loss. In more severe cases, fistulas or abscesses can form in the lower right quadrant of the abdomen.
• Colitis: Inflammation in the lining of the large intestine. Symptoms may include frequent bowel movements, diarrhea and rectal bleeding. Some people may also develop fistulas, ulcers, or abscesses around the anus.
• Jejunitis: Spots of inflammation in the upper half of the small intestine. Symptoms may include diarrhea and abdominal pain or cramps, especially after eating.
• Perianal disease: Inflammation around the anus. Symptoms may include the development of fistulas or abscesses around the anus.

The exact cause of Crohn’s disease is not fully understood, but it is believed to involve several factors leading to an abnormal immune response. Some of these factors include:

• Abnormal immune response
• Genetics
• Microbiome (the community of tiny living things, like bacteria, that live in and on your body) 
• Environmental factors

In people with Crohn’s disease, it is possible that the immune system mistakenly attacks harmless bacteria that are normally found in the body. The immune system attacks the digestive tract, too. Researchers have also linked more than 200 genes to Crohn’s disease that may increase a person’s likelihood of developing the condition.¹

Anyone can be diagnosed with Crohn’s disease; however, Crohn’s disease is often diagnosed in younger adults, with many cases identified before age 30. Other known risk factors include having a family history of the disease, cigarette smoking, and regular use of nonsteroidal anti-inflammatory drugs (NSAIDs), like ibuprofen. Crohn’s disease has been reported more often in people of Eastern European Jewish descent, with increasing rates also seen in African American and Middle Eastern populations.

Crohn’s disease can sometimes lead to complications that may require additional treatment or surgery. Possible complications include:

• Ulcers: Open sores that can develop in the mouth, anus or genital area.
• Fistulas: Abnormal tunnel-like connections between parts of the body that do not normally connect. These most often occur near the anus.
• Bowel Obstructions: Partial or complete blockages of the intestine that can occur when inflammation or scar tissue causes the bowel to narrow. These narrowed areas are called strictures and may sometimes require surgery.
• Anal Fissure: Small tears in the skin around the anus that can cause pain, bleeding, or itching, especially during bowel movements.
• Malnutrition: Ongoing inflammation, abdominal pain, and diarrhea can make it hard to eat and absorb nutrients. This may lead to problems such as anemia, which is a result of low iron, or low vitamin B-12 levels.
• Colon Cancer: People with Crohn’s disease that affects the colon have a higher risk of colon cancer and may need more frequent colonoscopy screenings.

Crohn’s disease may also increase the risk of other health problems, including blood clots, skin conditions, osteoporosis, arthritis, kidney stones and gallbladder or liver disease. While these complications are not usually life-threatening, it is important to monitor symptoms closely and talk with a healthcare provider about any concerns.

If you have Crohn’s disease, some foods may help reduce symptoms while others may make them worse. There is no single diet that causes symptoms for everyone, but some people find that dairy products, carbonated drinks, caffeine and alcohol can trigger symptoms. Eating lower-fat foods, staying well hydrated and choosing smaller, more frequent meals may help ease digestive discomfort.

Multivitamins or other supplements may be helpful, since Crohn’s disease can affect how the body absorbs nutrients. Food triggers vary from person to person, so keeping a food diary can help you learn which foods are easier on your digestive system. A healthcare provider or dietitian can also help you create a meal plan that works best for you.

Lifestyle choices can play an important role in managing Crohn’s disease and reducing flare-ups. Avoiding smoking is especially important, as smoking can worsen symptoms and increase the risk of complications. Limiting alcohol and avoiding foods that trigger symptoms may also help reduce discomfort. Some medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), can irritate the digestive tract and may make symptoms worse.

Taking care of both mental and physical health is also important. Many people with Crohn’s disease experience stress, anxiety, or depression, especially during flare-ups, which can make symptoms harder to manage. Getting enough rest, staying physically active and practicing regular relaxation and breathing techniques can all help support symptom control and improve overall quality of life.

Most people see a doctor because of ongoing symptoms such as abdominal cramping, persistent diarrhea, or unexplained weight loss. These symptoms can occur in many other conditions, so healthcare professionals will usually start with ruling out other possible causes. This often includes reviewing medical and family history and performing a physical exam to check for tenderness or swelling in the abdomen.

There is no single test that can diagnose Crohn’s disease, so doctors use a combination of tests to confirm the diagnosis. These tests may include:

• Blood Tests: Check for signs of infection, anemia, inflammation, and liver function.
• Stool Tests: Look for blood, bacteria, parasites, and markers of inflammation.
• Colonoscopy: Allows doctors to examine the inside of the colon and lower part of the small bowel. May collect tissue samples (biopsies) for laboratory analysis.
• Upper Endoscopy: Examines the upper digestive tract, from the mouth to the beginning of the small intestine.
• Capsule Endoscopy: Involves swallowing a small plastic capsule containing a camera that takes pictures as it moves through the digestive tract.
• Computed Tomography (CT) Scan: Provides detailed images of the bowel and tissue outside of the bowel to assess the extent and severity of inflammation.
• Magnetic Resonance Imaging (MRI): Often used to evaluate fistulas, particularly around the anal area or small intestine.

Crohn’s disease is a lifelong condition, but its course can be very different from person to person. With the right treatment and regular medical care, many people are able to manage symptoms, reduce inflammation, and maintain a good quality of life. There is no cure for Crohn’s disease, but advances in treatment are helping improve long-term outcomes and lower the risk of complications. Some people may still have flare-ups or develop complications over time, which can require changes in treatment or surgery. Working closely with a healthcare provider to monitor the disease and adjust treatment as needed is an important part of managing Crohn’s disease over the long term.

While ulcerative colitis and Crohn’s disease can be similar in their symptomatic presentation, they each impact different areas of the gastrointestinal tract and in different ways. Crohn’s disease can affect any part of the gastrointestinal tract, anywhere from your mouth to your anus. Additionally, it can affect all layers of the bowel wall including the deeper layers. Ulcerative colitis only impacts the colon and rectum and is generally limited to the inner lining of the bowel.

Researchers are continuously investigating potential new and more effective treatments. For guidance on the best treatment options for you—and to determine if you may qualify for a clinical trial—please speak with your healthcare provider.