Symptoms

By Mayo Clinic staff

   

Crohn's disease is an inflammatory bowel disease (IBD). It causes inflammation of the lining of your digestive tract, which can lead to abdominal pain, severe diarrhea and even malnutrition. Inflammation caused by Crohn's disease can involve different areas of the digestive tract in different people.

The inflammation caused by Crohn's disease often spreads deep into the layers of affected bowel tissue. Like ulcerative colitis, another common IBD, Crohn's disease can be both painful and debilitating, and sometimes may lead to life-threatening complications.

While there's no known cure for Crohn's disease, therapies can greatly reduce the signs and symptoms of Crohn's disease and even bring about long-term remission. With treatment, many people with Crohn's disease are able to function well.

 

 

Inflammation of Crohn's disease may involve different areas in different people. In some people, just the small intestine is affected. In others, it's confined to the colon (part of the large intestine). The most common areas affected by Crohn's disease are the last part of the small intestine (ileum) and the colon. Inflammation may be confined to the bowel wall, which can lead to scarring (stenosis), or inflammation may spread through the bowel wall (fistula).

 

Signs and symptoms of Crohn's disease can range from mild to severe and may develop gradually or come on suddenly, without warning. You may also have periods of time when you have no signs or symptoms (remission). When the disease is active, signs and symptoms may include:

 

  • Diarrhea. The inflammation that occurs in Crohn's disease causes cells in the affected areas of your intestine to secrete large amounts of water and salt. Because the colon can't completely absorb this excess fluid, you develop diarrhea. Intensified intestinal cramping also can contribute to loose stools. Diarrhea is a common problem for people with Crohn's.
  • Abdominal pain and cramping. Inflammation and ulceration may cause the walls of portions of your bowel to swell and eventually thicken with scar tissue. This affects the normal movement of contents through your digestive tract and may lead to pain and cramping. Mild Crohn's disease usually causes slight to moderate intestinal discomfort, but in more-serious cases, the pain may be severe and include nausea and vomiting.
  • Blood in your stool. Food moving through your digestive tract may cause inflamed tissue to bleed, or your bowel may also bleed on its own. You might notice bright red blood in the toilet bowl or darker blood mixed with your stool. You can also have bleeding you don't see (occult blood).
  • Ulcers. Crohn's disease can cause small sores on the surface of the intestine that eventually become large ulcers that penetrate deep into — and sometimes through — the intestinal walls. You may also have ulcers in your mouth similar to canker sores.
  • Reduced appetite and weight loss. Abdominal pain and cramping and the inflammatory reaction in the wall of your bowel can affect both your appetite and your ability to digest and absorb food.

 

Other signs and symptoms
People with severe Crohn's disease may also experience:

 

  • Fever
  • Fatigue
  • Arthritis
  • Eye inflammation
  • Mouth sores
  • Skin disorders
  • Inflammation of the liver or bile ducts
  • Delayed growth or sexual development, in children

 

The exact cause of Crohn's disease remains unknown. Previously, diet and stress were suspected, but now doctors know that although these factors may aggravate existing Crohn's disease, they don't cause it. Now, researchers believe that a number of factors, such as heredity and a malfunctioning immune system, play a role in the development of Crohn's disease.

 

  • Immune system. It's possible that a virus or bacterium may trigger Crohn's disease. When your immune system tries to fight off the invading microorganism, an abnormal immune response causes the immune system to attack the cells in the digestive tract, too.
  • Heredity. Crohn's is more common in people who have family members with the disease, leading experts to suspect that one or more genes may make people more susceptible to Crohn's disease. However, most people with Crohn's disease don't have a family history of the disease.

  • Risk factors for Crohn's disease may include:

  • Age. Crohn's disease can occur at any age, but you're likely to develop the condition when you're young. Most people who develop Crohn's disease are diagnosed before they're 30 years old.
  • Ethnicity. Although whites have the highest risk of the disease, it can affect any ethnic group. If you're of Eastern European (Ashkenazi) Jewish descent, your risk is even higher.
  • Family history. You're at higher risk if you have a close relative, such as a parent, sibling or child, with the disease. As many as 1 in 5 people with Crohn's disease has a family member with the disease.
  • Cigarette smoking. Cigarette smoking is the most important controllable risk factor for developing Crohn's disease. Smoking also leads to more severe disease and a greater risk of surgery. If you smoke, stop. Discuss this with your doctor and get help. There are many smoking-cessation programs available if you are unable to quit on your own.
  • Where you live. If you live in an urban area or in an industrialized country, you're more likely to develop Crohn's disease. Because Crohn's disease occurs more often among people living in cities and industrial nations, it may be that environmental factors, including a diet high in fat or refined foods, play a role in Crohn's disease. People living in northern climates also seem to have a greater risk of the disease.