Crohn's Disease

Medically Reviewed By William C. Lloyd III, MD, FACS
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What is Crohn’s disease?

Crohn’s disease is a chronic inflammation of the gastrointestinal tract and one form of inflammatory bowel disease. In Crohn’s disease, the body’s immune system mistakenly attacks healthy tissues in response to food or infection in the digestive tract. The disease can affect any part of the gastrointestinal tract, but it most commonly affects the lower portion of the small intestine (the ileum). Other areas affected include the mouth, esophagus, stomach, small intestine, large intestine, and rectum.

Symptoms often have an insidious onset and happen in intermittent bouts over a lifetime. The frequency and intensity of symptoms steadily progress over time. Delay in diagnosis is common due to the diverse pattern of symptoms. Classic symptoms of Crohn’s disease include abdominal pain and swelling and frequent episodes of diarrhea. The disease can also cause inflammatory conditions elsewhere in the body (joints, eye, skin and liver) that require treatment.

Crohn’s disease can seriously affect a person’s ability to participate in normal daily activities and can lead to serious complications including malnutrition and blockage in the intestines. Children who have Crohn’s disease may experience growth problems.

The exact cause of Crohn’s disease is not known, but researchers believe it may be an autoimmune disorder that tends to run in families; about 20% of people with Crohn’s disease have a blood relative with some form of inflammatory bowel disease. Crohn’s disease can affect all age groups but especially young adults ages 15 to 35.

Chronic inflammation of the gastrointestinal tract due to Crohn’s disease damages the inner lining of parts of the digestive system. It can lead to serious or life-threatening complications, such as nutritional deficiencies, gastrointestinal bleeding, anemia, and bowel obstruction.

Seek prompt medical care if you have symptoms of Crohn’s disease, such as abdominal pain and frequent diarrhea. Seek immediate medical care (call 911) if you, or someone you are with, have severe bleeding from the rectum, severe and constant abdominal pain, or an unusual change in alertness.

What are the symptoms of Crohn’s disease?

Symptoms of Crohn’s disease are due to the chronic inflammation and irritation of the gastrointestinal tract. Everyone with Crohn’s disease experiences it differently. Symptoms may be mild, moderate or severe. In fact, they may be more or less severe at different times in the same person. Symptoms can range from mild to severe and include:

Common symptoms of Crohn’s disease

If you have Crohn’s disease, you may experience the following common symptoms:

  • Abdominal pain and cramping (often involving the right lower quadrant)
  • Diarrhea, which may be bloody or have pus in it
  • Weight loss

Symptoms can range from mild to severe and include:

  • Anemia
  • Eye discomfort and inflammation (uveitis)
  • Failure to thrive in children, marked by slow growth and development of severe Crohn's
  • Fatigue
  • Nutritional deficiencies
  • Pain with bowel movements

  • Weight loss

Other symptoms include mouth sores, rectal bleeding, signs of osteoporosis, or signs of kidney or liver disease, such as hepatitis or cirrhosis.

Serious symptoms that might indicate a life-threatening condition

In some cases, Crohn’s disease can lead to serious complications, such as dehydration, bowel obstruction, anemia, and peritonitis (infection of the lining that surrounds the abdominal cavity). Seek immediate medical care (call 911) if you, or someone you are with, are experiencing any of the following life-threatening symptoms:

  • Severe, constant abdominal pain or cramping that may occur with bloating, vomiting, constipation or diarrhea
  • Unusual change in level of consciousness or alertness

What causes Crohn’s disease?

The exact cause of Crohn’s disease is not known, but researchers believe it may be an autoimmune disease caused by an abnormal immune system response to a bacterial infection or food in the gastrointestinal tract. Although some evidence indicates that people with this disease have abnormalities of the immune system, it is not known whether the immune problems are a cause or a result of the disease.

Crohn’s disease may also run in families, so there is likely a genetic component. Some people may be born with certain genes that predispose them to developing Crohn’s disease. If you have a parent, brother or sister with Crohn’s disease, you’re more likely to develop it yourself.

Environmental factors may play a small role in Crohn’s. Potential factors include smoking; taking antibiotics, nonsteroidal anti-inflammatories (NSAIDs like ibuprofen), or oral birth control; or eating a high-fat diet.

Despite popular belief, Crohn’s disease is not caused by eating certain foods, although some foods can irritate the bowel and intensify symptoms in people who already have the disease. Irritating foods vary depending on the individual. Crohn’s is also not caused by excessive stress.

What are the risk factors for Crohn’s disease?

A number of factors increase the risk of developing Crohn’s disease. Not all people who are at risk for Crohn’s disease will develop the condition. Risk factors include:

  • Family history of Crohn’s disease
  • Jewish ancestry
  • Smoking

Reducing your risk of Crohn’s disease

Although there are some known risk factors for Crohn’s, it is not a disease you can prevent. A healthy lifestyle and treatment plan may help manage the disease and prevent flare-ups, which will ease symptoms. Components of a healthy lifestyle include:

  • Eating a well-balanced diet
  • Exercising most days of the week, which will help decrease stress and keep off excess weight
  • Managing stress

What are some conditions related to Crohn’s disease?

Crohn’s disease is one form of inflammatory bowel disease (IBD). The other is ulcerative colitis (UC), which affects the large bowel. Doctors are not sure what causes UC, but they know the immune system acts abnormally in people with ulcerative colitis. Research suggests the gut microbiome—bacteria, fungi and viruses that live in the digestive tract—may play a role in why some people develop IBD and others do not. The genes a person is born with are also important in ulcerative colitis, as it tends to run in families.

A condition with symptoms like IBD is irritable bowel syndrome (IBS). Symptoms of irritable bowel syndrome include abdominal pain, discomfort, bloating, and fullness. Stool consistency varies with IBS. Some people experience constipation and bloating, while others experience diarrhea and fecal urgency. In contrast to IBD, irritable bowel syndrome does not damage the intestines or lead to systemic inflammation. As a result, tissue biopsies are usually nondiagnostic with IBS. Nevertheless, IBS is challenging and can lead to reduced quality of life. IBS treatment (medication and self-care) can help control symptoms.

How do doctors diagnose Crohn’s disease?

People who experience chronic abdominal pain, diarrhea, fever, weight loss, and anemia should be examined for signs of Crohn's disease. In addition to a complete medical history and physical exam, Crohn's disease diagnostic tests and procedures may include:

  • Stool culture: Checks for the presence of abnormal bacteria in the digestive tract that may cause diarrhea and other problems.
  • Esophagogastroduodenoscopy (also called EGD or upper endoscopy): Allows the physician to examine the inside of the esophagus, stomach, and duodenum and remove tissue or cells for further examination (biopsy).
  • Colonoscopy: Allows the physician to view the entire length of the large intestine and can often help identify abnormal growths, inflamed tissue, ulcers, and bleeding. This procedure also allows the physician to perform a biopsy.
  • Upper GI series: Examines the organs of the upper part of the gastrointestinal system: the esophagus, stomach, and duodenum (the first section of the small intestine).
  • Lower GI series: Examines the rectum, large intestine, and lower part of the small intestine.

You will likely see a gastroenterologist for your physical exam and other tests. You doctor may ask the following types of questions:

  • How long have you experienced symptoms?
  • When do your symptoms occur?
  • Are your symptoms worsened or relieved by what you eat?
  • How is your mood?
  • Are you in pain? How often? (Prepare to rate your pain on a scale from 0 to 10, with 0 being no pain and 8 to 10 severe pain.)

How is Crohn’s disease treated?

There is no cure for Crohn’s disease, but there are several options to help control it. Treatment is aimed at minimizing symptoms and complications by reducing bowel inflammation and ensuring good nutrition and hydration. Following your individual treatment plan can relieve symptom flare-ups, producing long-term, symptom-free periods of remission.

Drug treatment of Crohn’s disease

Crohn’s disease can be treated with a variety of drugs including:

  • Aminosalicylic acids (5-ASA), such as mesalamine, olsalazine and balsalazide, for mild to moderate Crohn’s. Mesalamine comes as a pill you take by mouth, a suppository you place in the rectum, and as an enema. Most people can take them for a long time. Side effects include diarrhea, headache, heartburn, nausea, vomiting, and abdominal pain.
  • Biologics are the newest kinds of Crohn’s drugs. They include adalimumab, certolizumab, infliximab and infliximab-dyyb, natalizumab, and vedolizumab.They also help reduce inflammation, but they do so by targeting a specific protein. Side effects may include diarrhea, headaches, heartburn, nausea, vomiting, abdominal pain, and a risk of getting infections such as tuberculosis.
  • Corticosteroids, such as prednisone. Corticosteroids are effective in controlling acute flare-ups but not in maintaining remissions. These anti-inflammatory drugs are more powerful than 5-ASAs and can have serious side effects, such as increased susceptibility to infection and osteoporosis, so they are generally used only in short courses.
  • Immune system suppressors (immunomodulators), such as azathioprine, cyclosporine, 6-mercaptopurine, and methotrexate, which decrease gastrointestinal inflammation but take several weeks to months to start working. Potential side effects can be severe and include fatigue, nausea, vomiting, pancreatitis, and a higher chance of developing infections. Cyclosporine, in particular, has serious side effects, so doctors do not prescribe it on a long-term basis.
  • Medications with an anti-diarrheal effect, such as codeine and loperamide
  • Vitamins and other nutritional supplements to address or minimize nutritional deficiencies and malnutrition

Be sure to consult your doctor before using any over-the-counter (OTC) products, especially pain relievers and anti-diarrheals, to relieve your symptoms.

Other treatments of Crohn’s disease

Crohn’s disease is also treated with a variety of therapies, lifestyle and dietary interventions, and possibly surgery. Other treatments of Crohn’s disease include:

  • Antibiotics to treat infections from abscesses or fistulas
  • Dietary changes, such as drinking extra fluids to prevent dehydration, eating a low-fat diet, and limiting dairy products and any other foods that seem to aggravate your symptoms
  • Intravenous nutrition to ensure adequate nutrition if you are unable to eat because you need to let your gastrointestinal tract rest
  • Intravenous rehydration and electrolyte replacement if frequent diarrhea has resulted in the loss of excessive fluid and electrolytes, causing severe dehydration and electrolyte imbalances
  • Regular exercise to improve both physical and mental well-being
  • Regular medical care to monitor symptoms, modify treatment plans as needed, and watch for possible complications
  • Surgery to control Crohn’s disease when dietary and lifestyle changes and medications do not reduce severe symptoms or when there are complications, such as fistula formation. Surgical procedures include partial small bowel resection; partial colectomy, in which a portion of the colon (large bowel) is removed; or total colectomy, in which the entire colon is removed. A colostomy is necessary to allow stool to leave the body.

There is no way to predict when a remission may occur or when symptoms will return. Symptoms of the disease may resemble other medical conditions or problems, so it's important to contact a doctor when Crohn's disease flares up.

With your doctor’s help, you can expect to manage your Crohn’s disease symptoms with fairly few problems. Always follow treatment instructions, and report any changes in your symptoms or the effectiveness of your medication. By finding the right treatment plan for you, you can have control over your Crohn’s symptoms—instead of letting them have control over you.

What are the diet and nutrition tips for Crohn’s disease?

The foods you ate before you were diagnosed with Crohn’s didn’t necessarily cause the condition, but watching what you eat after diagnosis can help you feel better and get the nutrients you need for optimal health. Crohn’s symptoms, such as a lack of appetite, may make it harder for you to eat a healthy diet, while diarrhea can make it tougher for the body to digest what it needs to thrive. Ask your healthcare provider or a registered dietitian for guidance before making significant changes to your diet.

For people dealing with Crohn’s symptoms, doctors recommend:

  • Bland food, not spicy food
  • Low-fiber foods, not foods high in fiber
  • Limiting or eliminating dairy, especially if you are lactose intolerant

If serious Crohn’s symptoms continue despite changes to your diet, your physician may recommend a bowel rest. This rest is to give your GI tract a break in processing foods to soothe GI tract inflammation and allow the tissues to heal. It consists of a liquid-only diet that can last up to a few weeks, and may take place in a hospital or at home. You may drink a nutrient-filled liquid, either by mouth or via feeding tube, or you may be given nutrition intravenously through a needle in a vein.

How does Crohn’s disease affect quality of life?

The emotional aspects of living with Crohn’s disease can also be distressing. People with Crohn’s disease may often find themselves struggling with stressful issues such as:

  • Inability to predict when a symptom flare-up will occur
  • Fears about going out in public: Will you find a bathroom if you suddenly need it? If not, what will you do? What if you have an “accident”? How will you handle an attack of severe pain?
  • Concern that your symptoms or treatment may interfere with your sex life
  • Depression and other emotional issues connected with having a lifelong disease
  • Other health concerns, such as the need to watch for symptoms of malnutrition (for example, weight loss) due to intestinal damage

Today’s treatments can be very effective and limit the emotional distress of Crohn’s disease. Still, life with Crohn’s disease can be challenging. Talk to your doctor about your experience with Crohn’s, and which treatments might be best for you.

Maintaining or creating a good support system is vital to living a full, healthy life with Crohn’s disease.

What are the potential complications of Crohn’s disease?

Complications of Crohn’s disease can be serious or life-threatening. Complications can include:

  • Anemia
  • Bowel obstruction
  • Dehydration
  • Deterioration of bowel function
  • Disability
  • Fistulas, which are abnormal holes between the gastrointestinal tract and other areas of the body, such as the vagina, bladder and skin. Fistulas can easily become seriously infected and cause other problems.
  • Growth problems in children
  • Malnutrition
  • Peritonitis (infection of the lining that surrounds the abdominal cavity)
  • Rectal bleeding
  • Shock

Does Crohn’s disease shorten life expectancy?

Finding a good Crohn’s doctor and the right treatment plan helps people manage Crohn’s symptoms. However, the unpredictable nature of Crohn’s symptoms, pain and complications can shorten life expectancy. In a 2020 Canadian study of inflammatory bowel disease (IBD), life expectancy was 6 to 8 years shorter in females with IBD than without the condition; in males, the difference was 5 to 6 years. However, life expectancy of people with IBD, particularly Crohn’s disease, increased from 1996 to 2011.

In the same study, the effect of pain on daily functioning had a significant impact on health-adjusted life expectancy, which takes into account quality of life. Health-adjusted life expectancy is the number of years a person can expect to live in full health. Although biologics have a positive impact on life expectancy for some populations, pain control should be a cornerstone of care for people with Crohn’s disease and may improve life expectancy overall.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Apr 14
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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