Crohn’s disease is an inflammatory bowel disease that causes inflammation and irritation in the lining of the gastrointestinal (GI) tract. It commonly affects the small and large intestine, but can occur at any point from the mouth to the anus. It tends to worsen over time, but periods of remission (where symptoms disappear) may last weeks or years. Though it can develop in anyone at any age, a person is more likely to develop it in their twenties. Additional risk factors include smoking and family history of inflammatory bowel disease.

Crohn’s disease can increase the risk of developing colon cancer, fistulas (abnormal tunnels in the GI tract), abscesses, anal fissures (small tears), intestinal obstructions, and inflammation in other areas of the body.^[1]

The most common symptoms of Crohn’s disease are diarrhea (occasionally bloody), abdominal pain and cramping, and unexplained weight loss. Other potential signs and symptoms include nausea, reduced appetite, joint or eye pain, fatigue, anemia, or fever.^[2]

After gathering a medical history, a doctor (usually a gastroenterologist) will perform a number of exams and tests to diagnose Crohn’s Disease. They will likely start with a physical exam to check for bloating and abdominal tenderness and listen to the sounds of the GI tract. Other diagnostic tests may include blood tests to detect anemia and inflammation, stool tests to rule out other diseases, endoscopies (such as a colonoscopy) to view the GI tract lining and collect biopsies, or imaging tests such as a computed tomography (CT) scan.^[3]

There is no cure for Crohn’s Disease, but it can be managed with long-term care from a gastroenterologist, and medications that suppress the immune system or interrupt inflammatory processes to prevent damage to the intestinal lining and, in some cases, initiate remission. One noteworthy class of drugs is TNF-alpha inhibitors, such as infliximab.^[4]

Anti-diarrheal medications and acetaminophen (also known as paracetamol or the brand name Tylenol) can be used to treat diarrhea and abdominal pain, and antibiotics are used to treat infections that might occur (such as abscesses). Fistulas, anal fissures, and ulcers can be treated with medication and dietary modifications, but in some cases, severely damaged sections of the intestine may need to be surgically removed and rerouted or attached to a reservoir to enable the passage of stool.

Severe symptoms may also require bowel rest, which can involve partial enteral nutrition — using specific liquid formulas to meet a patient’s dietary needs — or delivering nutrients intravenously to bypass the GI tract completely. Partial enteral nutrition may help to prevent flares when a patient is in remission, especially when fed through a nasogastric tube that delivers the formula directly into the stomach through the nose.^[5][6]

Probiotics, prebiotics, and synbiotics have all been studied for IBD, but they appear to be much more effective in ulcerative colitis than in Crohn’s disease.^[7][8] Resveratrol could improve both GI symptoms and quality of life.^[9][10] Finally, there's a trial that suggested that boswellia may reduce disease activity to a similar degree to mesazaline, but more evidence is required to confirm these findings.^[11]

No specific dietary interventions are recommended for people with Crohn’s disease. The specific carbohydrate diet and Mediterranean diet were equally effective when comparing six-week remission rates, while the autoimmune protocol diet improved quality of life. However, these studies lacked control groups, and because Crohn’s disease can enter remission spontaneously, it’s unclear whether the diets caused remission.^[12][13]

A low-FODMAP diet may reduce some GI symptoms, but doesn’t reduce disease activity.^[14] Other exclusion diets — like those that remove carrageenan or animal products or require the use of organic foods — have little to no effect on IBD disease activity or remission rates.^[15]

People with Crohn’s disease may have lower circulating levels of fat-soluble vitamins A, D, E, and K, and low vitamin A status was associated with higher levels of C-reactive protein in one meta-analysis.^[16] Additionally, they might not be eating adequate calories, so supplementation may be recommended.^[17]

Fecal microbiota transplants appear effective for inducing remission in IBD, but most of the available trials for Crohn’s disease lack control groups, so more confirmatory trials are needed.^[18]

Both mindfulness exercises and cognitive behavioral therapy can improve quality of life, and regular exercise is an effective way to manage disease-related fatigue.^[10][19][20]

Although hyperbaric oxygen therapy is associated with remission and clinical improvements in Crohn’s disease, most studies have serious design flaws (like a lack of randomization or control groups), so it’s unclear whether those occurred as a result of the treatment or as a normal part of the disease process.^[21]

The cause of Crohn’s Disease is unknown, but researchers believe it could be due to an autoimmune reaction potentially triggered by gut microbes, and that genes could also play a role.

In observational studies, a Western dietary pattern is associated with an increased risk of developing Crohn’s disease, while dietary fiber, fruit, vegetable, and fish intake are associated with a reduced risk.^[22][23][24]

Smoking may double the chances of developing Crohn’s disease, while other lifestyle factors — such as non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, and certain types of birth control pills — may increase the risk, but only slightly.^[2]