Crohn's Disease

What Are the Symptoms of Crohn's Disease?

People with Crohn's disease can experience periods of severe symptoms followed by periods of remission that can last for weeks or years. The symptoms of Crohn's disease depend on where the disease occurs in the bowel and its severity. In general, symptoms can include:

Other symptoms can develop, depending on complications related to the disease. For example, a person with a fistula (abnormal passageway between various organs or tissues) in the rectal area may have pain and leaking discharge around the rectum.

Severe inflammation and obstruction of various parts of the gastrointestinal tract due to swelling and scar formation can cause other problems like bowel perforation, abdominal distension (swelling), severe pain, and fever. This can be life-threatening.

Crohn’s is a disorder of uncertain etiology. It has often been thought of as an autoimmune disease but research suggests that the chronic inflammation may not be due to the immune system attacking the body itself, but rather a result of the immune system attacking harmless virus, bacteria or food in the gut causing inflammation that leads to bowel injury. Crohn's disease can cause other parts of the body to become inflamed (due to chronic inflammatory activity) including the joints, eyes, mouth, and skin. In addition, gallstones and kidney stones may also develop as a result of Crohn's disease.

Moreover, children with the disease may experience decreased growth or delayed sexual development.

What Causes Crohn's Disease?

The cause of Crohn's disease is unknown. However, it is likely due to an abnormal response of the immune system. Food or bacteria in the intestines, or even the lining of the bowel may cause the uncontrolled inflammation associated with Crohn's disease.

Who Gets Crohn's Disease?

Crohn's disease is often inherited. About 20% of people with Crohn's disease may have a close relative with either Crohn's or ulcerative colitis. In addition, Jewish people of European descent (Ashkenazi) are at greater risk for the disease.

While Crohn's disease can affect people of all ages, it is primarily an illness of the young. Most people are diagnosed before age 30, but the disease can occur in people in their 50's, 60's, 70's, or even later in life.


How Is Crohn's Disease Diagnosed?

A variety of diagnostic procedures and lab tests are used to distinguish Crohn's disease from other inflammatory gastrointestinal conditions like ulcerative colitis.

First, your doctor will review your medical history. A specialist called a gastroenterologist may perform a colonoscopy or sigmoidoscopy to obtain bowel tissue for analysis. An upper endoscopy may also be done to look at the esopohagus, stomach and first part of the small intestine, the duodenum. A further look through the small intestine can be done with capsule endoscopy, which uses a small, pill-sized camera that is swallowed. Other tests your health care provider may order include:

  • Blood tests, including blood counts (often high white blood cell counts -- a sign of inflammation -- and low red blood cells counts -- a sign of anemia from blood loss -- are present).
  • Stool samples to rule out infections as the cause of diarrhea.
  • Special X-rays (such as a CT scan or MRI) of both the upper and lower gastrointestinal tract may be ordered as well to confirm the location of the inflammation.

What Triggers a Worsening of Crohn's Disease?

Crohn's disease is characterized by periods of having symptoms, which can last for days, weeks or months, interspersed with periods of remission when no symptoms are present. Remissions can last days, weeks, or even years.

Factors that worsen Crohn's disease include:

How Is Crohn's Disease Treated?

Though treatments cannot cure Crohn's disease, they can help most people lead normal lives.


Crohn's disease is treated primarily with medications, including:

  • Anti-inflammatory drugs, such as salicylates. Examples include mesalamine (Asacol, Lialda, Pentasa), olsalazine (Dipentum), and sulfasalazine (Azulfidine). Side effects include gastrointestinal upset, headache, nausea, diarrhea, or rash.
  • Corticosteroids, a more powerful type of anti-inflammatory drug. Examples include budesonide (Entocort), and prednisone or methylprednisolone (Solu-Medrol). Side effects, if taken for long periods of time, can be severe and may include bone thinning, muscle loss, skin problems, and increased risk of infection. Entocort has fewer side effects.
  • Immune system modifiers such as azathioprine (Imuran) or methotrexate (Rheumatrex). It can take up to six months for these drugs to work. These drugs are associated with increased risk of infections that can be life-threatening.
  • Antibiotics such as ciprofloxacin (Cipro), metronidazole (Flagyl), and others. Flagyl can cause a metallic taste in the mouth, nausea, and tingling or numbness of the hands and feet. Cipro can cause nausea and has been associated with rupture of the Achilles tendon.
  • Antidiarrheal drugs.
  • Biologic therapies, such as adalimumab (Humira), adalimumab-atto (Amjevita), a biosimilar to Humira, certolizumab pegol (Cimzia), infliximab (Remicade),  and infliximab-abda (Renflexis), or infliximab-dyyb (Inflectra), biosimilars  to Remicade. Remicade neutralizes the activity of a substance called tumor necrosis factor alpha (TNF-alpha). This substance is overproduced by people with Crohn's and plays an important role in causing the inflammation associated with Crohn's disease. The drug is given intravenously (through the vein). Side effects include life-threatening infection, infusion reaction, headache, stomach upset, fatigue, fever, pain, dizziness, rash, and itching.
  • There are other biologic alternatives to the anti-TNF blockers natalizumab (Tysabri) and vedolizumab (Entyvio) block alpha-4 integrin. Ustekinumab (Stelara) blocks IL-12 and IL-23.


Response to therapy is evaluated within several weeks of starting treatment. Treatment is continued until remission is obtained (at which time, the health care provider may consider maintenance therapy). No improvement calls for more aggressive therapy. Nutritional supplements may also be recommended by your doctor.


Surgery is eventually required in about two-thirds to three-quarters of people with Crohn's disease. Surgery is done to treat complications of the disease -- such as fistulas, abscesses, hemorrhage, and intestinal obstructions -- or to treat people who do not respond to medications.

In most cases, the diseased part of the bowel is removed and the two healthy ends of bowel are joined together (anastomosis). This surgery can allow many people to remain symptom-free for years, but it is not a cure since Crohn's disease often recurs at the site of the anastomosis.

Unfortunately, too many resection surgeries can lead to a condition called short gut syndrome where there isn't enough bowel left to adequately absorb nutrients.

An ileostomy may also be required if the rectum is diseased and cannot be utilized for an anastomosis. This is a connection of the intestine to the skin overlying the abdominal wall. The result is an opening in the skin from which waste products can be excreted into a specially designed pouch.

What Role Does Diet Play in Crohn's Disease?

While foods appear to play no role in causing Crohn's disease, soft, bland foods may cause less discomfort than spicy or high-fiber foods when the disease is active. Except for restricting milk in lactose intolerant people, most gastroenterologists try to be flexible in planning the diets of their Crohn's disease patients. Ask your doctor to create a dietary plan for you.



WebMD Medical Reference Reviewed by Minesh Khatri, MD on October 01, 2017



Crohn's & Colitis Foundation of America. "Crohn's Diagnosis & Testing."

FDA. “FDA approves Inflectra, a biosimilar to Remicade.” “FDA approves Amjevita, a biosimilar to Humira.”

National Digestive Diseases Information Clearinghouse. "Overview of the medical management of severe or refractory Crohn disease in adults."


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