Crohn's disease and ulcerative colitis are types of inflammatory bowel disease (IBD). They share similar symptoms, yet are two distinct conditions affecting different parts of the digestive tract. While the exact prevalence of Crohn’s disease is unknown, an estimated 3.1 million Americans, or 1.3% of the population, are affected by either Crohn’s disease or ulcerative colitis, up significantly from the two million Americans diagnosed just a few decades ago. Crohn’s disease affects men and women equally but is more common among Northern European and Anglo Saxon descendants. It typically develops before age 30.
Crohn's disease causes
The exact cause of Crohn's disease is unknown. Researchers believe that a combination of genetics, one's environment, and abnormal immune response play a role.
The following have been linked to the development of Crohn's disease:
- Abnormal immune response: The disease is associated with an abnormal immune response that causes inflammation along the digestive tract. This inflammation can affect the deeper layers of the gut, leading to symptoms like abdominal pain, changes in bowel movement, fatigue, and malabsorption.
- Genetics: There is a genetic component to Crohn’s, and the risk is greater for this condition than for ulcerative colitis. Studies found that between 5 and 20% of individuals with IBD have a parent, child, or sibling with either Crohn’s disease or ulcerative colitis.
- Environmental factors: For example, Crohn’s disease is more prevalent in developed countries compared to underdeveloped countries. It is more common in urban areas compared with rural areas. This condition is also more common in northern climates compared with southern climates.
- Cigarette smoking, birth control, and anti-inflammatory drugs: Smoking appears to contribute to the development of this condition, and may also trigger flare-ups. Oral contraceptives and anti-inflammatory drugs like ibuprofen or diclofenac are potential risk factors.
Diet and stress can aggravate Crohn’s disease symptoms, but do not cause the condition. On the other hand, breastfeeding seems to be protective and reduces one's risk.
Crohn’s disease symptoms
Symptoms last for days to weeks, and there may be periods of remission in which no symptoms exist. These acute episodes are unpredictable, range from mild to severe, and may last a few days or longer. Severe flare-ups are associated with intense pain, fever, fatigue, and dehydration.
When the disease is active, the following signs and symptoms may occur:
- Pain and cramping in the abdomen.
- Diarrhea, which can be bloody.
- Loss of appetite.
- Weight loss.
- Mouth sores.
- Children with Crohn’s disease may experience slow growth, pain in the joints, fever, and weakness before abdominal pain or diarrhea.
Crohn’s disease can also lead to:
- Inflammation of the joints, eyes, and skin.
- Inflammation of the liver and kidneys.
Crohn’s disease can lead to complications such as intestinal blockages, bowel rupture, collections of pus (abscesses), and fistulas. Fistulas are abnormal connections that form between the anus and the skin around the anus, or between two parts of the intestine. A person with Crohn’s disease is also at higher risk of developing colon cancer compared with someone without this condition.
Types of Crohn’s disease
The 5 Crohn’s disease types are classified based on the part of the intestine that is affected by inflammation.
- Ileocolitis: The end of the small intestine and a part of the large intestine is affected.
- Ileitis: Inflammation of the last part of the small intestine occurs.
- Gastroduodenal Crohn’s: The stomach and the first part of the small intestine is affected
- Jejunoileitis: Inflammation of the middle part of the small intestine occurs.
- Crohn's colitis: Only the large intestine is affected.
Crohn’s disease diagnosis
In addition to a physical exam and evaluation of the symptoms, doctors use several tests to rule out other conditions and confirm the diagnosis. Blood tests may show anemia, and stool tests can detect blood loss in the stool and infections. Practitioners also perform a colonoscopy, CT scans, and MRIs when they suspect Crohn’s disease. An endoscopy with biopsy confirms the diagnosis.
Crohn’s disease treatment
- Anti-inflammatory drugs: The first step to treating Crohn’s disease is using anti-inflammatory drugs, like corticosteroids or mesalamine.
- Immune suppressors: The next drugs considered are immune system suppressors, which reduce inflammation and target the immune system. Common immune system suppressors include azathioprine and methotrexate.
- Biologics: These are a newer class of drugs used for treating Crohn’s disease, and these drugs target specific proteins made by the immune system. Ustekinumab is the latest biologic approved for treating this condition.
- Other drugs are prescribed as needed: Fighting Crohn's may require other medications to help manage specific symptoms. For example, antibiotics are useful for infections, fistulas, and abscesses. Fiber supplements help manage diarrhea. Acetaminophen (Tylenol) helps with abdominal pain.
- Vitamins, iron, and other nutritional supplements manage malnutrition. Probiotics can help improve digestion and restore the gut flora after antibiotic therapy.
Severe cases require treatment in the hospital with intravenous fluids. Heavy bleeding is treated with blood transfusions. Many people with Crohn’s disease require surgery, and about one in two individuals will require a second surgery to manage complications of this disease. Surgery is indicated in case of intestinal blockage, to drain abscesses or close fistulas.
Crohn’s disease diet
A healthy lifestyle helps manage any chronic disease, including Crohn’s disease. Lifestyle factors that may help include a nutritious diet, regular exercise, good sleep, and stress management.
While there is no standard “Crohn's disease diet”, some foods can trigger or worsen the symptoms, and certain dietary changes can help. A dietician or nutritionist can recommend a diet to manage the condition and reduce the inflammation in the gut. It is best to keep a food journal and notice any links between certain foods and the onset of a flare-up.
The following tips may help with Crohn's disease management:
- Eat less fiber. Fiber, particularly insoluble fibers found in fruits with skin, seeds, whole grains, and raw vegetables, can be hard to digest for someone with Crohn’s disease. Replace high-fiber options with low-fiber foods like bananas, cantaloupe, cooked fruits, rice, corn, oatmeal, and potatoes.
- Go gluten-free. Adopting a gluten-free diet may also help. A large study found that two-thirds of the participants found improvement in symptoms, and 38% reported less severe flare-ups or fewer symptoms after dropping gluten.
- Avoid dairy. There are plenty of plant-based dairy alternatives to dairy, such as oat milk, almond milk, and cashew milk, available for those sensitive to dairy.
Other foods that can aggravate the symptoms include highly processed foods due to their high content of sugar, fats, and preservatives. Coffee, alcohol, and hot, spicy foods may cause abdominal discomfort and irritate the gut lining. While the low FODMAP diet helps manage irritable bowel syndrome, it can also be helpful for some people with Crohn’s disease.