Crohn’s Disease

Crohn’s Disease Overview

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:

  • Chronic diarrhea, often bloody and containing mucus or pus
  • Weight loss
  • Fever
  • Abdominal pain and tenderness
  • Feeling of a mass or fullness in the abdomen
  • Rectal bleeding

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 sigmoidoscopyto obtain bowel tissue for analysis. An upper endoscopymay 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:

  • Infections (including the common cold)
  • Cigarette smoking
  • Certain anti-inflammatory drugs (such as aspirin and ibuprofen)

How Is Crohn’s Disease Treated?

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

Medication

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

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.

Although there are many theories about what causes Crohn’s disease, none of them have been proven. There is a benefit, though, in understanding the possible causes of Crohn’s disease and how they interact with one another. Doing so can help one better understand the symptoms, diagnosis, and treatment of Crohn’s disease.

Scientists believe that Crohn’s disease is caused by a combination of these factors:

  • Immune system problems
  • Genetics
  • Environmental factors

How do immune system problems relate to Crohn’s disease?

Scientists have linked immune system problems to inflammatory bowel disease (IBD), including Crohn’s. Usually, cells of the immune system defend the body from harmful microbes — bacteria, viruses, fungi, and other foreign substances — that have entered it. The body doesn’t usually respond to all microbes, however. Many microbes are helpful, especially for digestion. And so the immune system leaves them alone.

If there is an invader that needs to be eliminated, your body’s defense reaction begins. This immune system response causes inflammation. Immune system cells, chemicals, and fluids flood to the site to overcome the offending substance. After the substance has been disabled or removed, the immune response ends. Inflammation subsides.

For some reason, though, people with Crohn’s disease have an immune system that reacts inappropriately. The immune system may be defending the body against helpful microbes by mistake. Or, for some other reason, the inflammatory response simply will not stop. Either way, over time, this chronic inflammation in the digestive system can result in ulcers and other injuries to the intestines.

Is genetics connected to Crohn’s disease?

Brothers, sisters, children, and parents of persons with IBD, including Crohn’s disease, are slightly more likely to develop the disease themselves. About 10% to 20% of people with Crohn’s disease have at least one other family member who also has the disease. The condition is more common in certain ethnic groups, such as Jews, and is more prevalent in Caucasians.

Scientists have identified a gene associated with Crohn’s disease. This gene helps the body decide how to react to certain microbes. If the gene has changed or mutated in some way, your body’s reaction to microbes may also be different from the normal reaction. Over time, IBD or Crohn’s disease may develop. People with Crohn’s disease have this mutated gene twice as often as people who do not have the disease.

Do environmental factors play a role in Crohn’s disease, too?

Environmental factors may help trigger Crohn’s disease. Also, it should be noted that because a potential trigger is linked or associated to a condition does not mean that it causes it. Associated environmental factors may include any of the following:

  • Substances from something you’ve eaten
  • Microbes such as bacteria or viruses
  • Cigarette smoke
  • Other substances that are yet unknown

Environmental factors may contribute to Crohn’s disease in one of these two ways:

  • They may trigger an immune system response. Once started, the response cannot stop.
  • They may directly damage the lining of the intestines. This may cause Crohn’s disease to begin or to speed up.

What can I do to control Crohn’s disease?

The factors involved in causing Crohn’s disease are complex. Scientists continue to seek more information about the causes — in hopes of finding better ways to diagnose, treat, and perhaps even cure this frustrating and painful disease. In the meantime, understanding current theories about the causes of Crohn’s disease can help you work with your doctor to explore how various treatments might work to control this condition.​

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