Everything You Need to Know About Crohn’s Disease


Crohn’s disease is a persistent condition that triggers inflammation in the gastrointestinal (GI) system and affects approximately 780,000 individuals in the United States. It is typically identified in individuals between the ages of 15 and 35.

Dr. Burrill B. Crohn, the namesake of the disease, and his colleagues initially documented it in 1932. Inflammatory bowel disease (IBD) includes only two types of conditions: Crohn’s disease and ulcerative colitis, which impacts an estimated 3.1 million Americans.

Even though Crohn’s disease has the potential to impact any area of the digestive system, it is more frequently observed in the small and large intestines.

Signs and Symptoms

Crohn’s disease symptoms usually emerge gradually, with severity varying from mild to severe, and can alternate between active and asymptomatic periods. The chronic inflammation of the digestive system caused by the disease frequently results in two prevalent symptoms: abdominal pain and diarrhea, which can be intense. The diarrhea may contain mucus or pus and be bloody.

Additional symptoms that may arise from Crohn’s disease include:

  • Fever;
  • Unexplained weight loss;
  • Bleeding from the rectum;
  • Fatigue, and;
  • Delayed growth and development in children.

Risk Factors

The exact cause of Crohn’s disease remains unknown, but it is believed to be autoimmune-mediated. This means that the body attacks its own tissues or organs. In the case of Crohn’s disease, it is hypothesized that the immune system mistakenly reacts to a harmless bacteria in the gut, triggering an overzealous response that extends to involve the tissues of the digestive system and other bodily systems.

Although the cause of Crohn’s disease is unclear, there are established risk factors for developing the disease. These include age, with the majority of individuals diagnosed under the age of 30, and family history/ethnicity, with five to 20 percent of patients having a first-degree relative with IBD. Additionally, Caucasians and Ashkenazi Jews are at a higher risk. Smoking is another modifiable risk factor that not only increases the risk of developing Crohn’s disease but also may increase the severity of the disease. Finally, environment may also play a role, with individuals living in urban areas or industrialized countries having a higher risk.

Screening and Prevention

At present, there are no official recommendations for screening Crohn’s disease. However, the absence of such guidelines does not indicate a lack of interest in developing screening methods, given that delayed diagnosis is a common issue.

The introduction of the Red Flags index, a clinical tool that has shown promise in detecting Crohn’s disease based on initial signs and symptoms, may prompt a change in this. Nevertheless, it is important to note that there is currently no way to prevent Crohn’s disease.

When to See a Doctor

If you are worried that you may have Crohn’s disease and have not yet received a diagnosis, it is important to schedule an appointment with your doctor. You should be especially concerned if you have persistent changes in your bowel movements and other symptoms that could indicate Crohn’s disease, such as abdominal pain, chronic diarrhea, unexplained weight loss, recurring fevers, and rectal bleeding or bloody stools.

If you have already been diagnosed with Crohn’s disease, you should contact your doctor if you experience dehydration, abdominal bloating, shaking chills, severe abdominal pain, or persistent diarrhea that lasts longer than two weeks. It is important to seek prompt medical attention if you experience any of these symptoms to manage your condition effectively.


To diagnose Crohn’s disease, doctors need to rule out other potential digestive system diseases that share similar signs and symptoms. As there isn’t a single test or examination to diagnose Crohn’s disease, your doctor will begin by taking your medical history and conducting a physical examination.

During your medical history, your doctor may ask about your current medications and if you experience any of the following:

  • Abdominal pain and/or cramping
  • Family history of IBD
  • Recurrent fevers
  • Recent weight loss and/or fatigue
  • Diarrhea and/or bloody stools

During the physical examination, your vital signs such as weight, temperature, blood pressure, and pulse will be taken. Your doctor will also conduct an abdominal and rectal examination.

Lab tests that your doctor may order include a complete blood count to check for anemia and the presence of infection. Other blood tests may include checking electrolytes, kidney and liver function, C-reactive protein or erythrocyte sedimentation rate, and iron and vitamin B12 levels. Your doctor may also collect a stool sample to check for the presence of microscopic blood or white blood cells and to rule out bacterial or parasitic infections.

Diagnostic procedures that your doctor may use include:

  • Colonoscopy, which visualizes the entire colon and allows for tissue sampling.
  • Abdominal computed tomography or magnetic resonance imaging.
  • Flexible sigmoidoscopy.
  • Video capsule endoscopy, which involves swallowing a capsule with a miniaturized video camera.
  • Balloon-assisted enteroscopy, which is most useful if video capsule endoscopy reveals potential disease, but the diagnosis of Crohn’s disease is still uncertain.


Determining which part of the gastrointestinal (GI) tract is affected by Crohn’s disease is crucial, as it can impact the symptoms, complications, and treatment options for individuals diagnosed with the disease. This variability in symptoms is due to the existence of five recognized types of Crohn’s disease, classified based on their location:

  1. Ileocolitis: Affects the ileum (the last part of the small intestine) and the colon, and is the most common type of Crohn’s disease, occurring in nearly 50 percent of patients.
  2. Ileitis: Affects only the ileum, and is present in almost 30 percent of Crohn’s patients.
  3. Crohn’s, or Granulomatous, Colitis: Affects only the colon and is found in almost 20 percent of patients.
  4. Gastroduodenal Crohn’s Disease: Affects the stomach and the duodenum (the first part of the small intestine), and is found in approximately five percent of patients.
  5. Jejunoileitis: Affects the jejunum (the middle of the small intestine), and is the rarest form of the disease.

Additionally, nearly 30 percent of Crohn’s patients have a variation known as perianal disease, which involves abnormal channels forming connections between organs and tissues, deep-seated tissue infections, and open sores in the skin surrounding the anus.


If you have received a diagnosis of Crohn’s disease, you may be at risk of developing a range of complications. Generally, these complications can be classified as either local, affecting only the intestines, or systemic, manifesting outside of the intestines.

Local Complications

Complications of Crohn’s disease that affect only the intestines are referred to as local complications, and they may include:

  • Abscesses: Pockets of pus that develop due to bacterial infections, often characterized by swelling, tenderness, pain, and fever.
  • Strictures: Narrowing of the bowel due to thickening of the bowel wall caused by chronic inflammation, which can lead to bowel obstruction.
  • Perforations: Holes in the wall of the small intestine or colon, which are considered a medical emergency.
  • Malabsorption: Can lead to anemia caused by iron and/or vitamin B12 deficiency.
  • Anal fissures: Painful tears in the skin around the anus that can become infected and lead to perianal fistulas.

Fistulas are abnormal connections between the intestines and other organs, which are also local complications of Crohn’s disease. They include:

  • Entero-vesical fistula: Intestines connect with the bladder, characterized by the passage of gas, blood, or stool during urination.
  • Entero-vaginal fistula: Intestines connect with the vagina, characterized by the passage of gas or stool through the vagina.
  • Entero-cutaneous fistula: Intestines connect with the skin, causing the drainage of stool through the skin.
  • Entero-enteric fistula: One portion of the intestines connects with another portion of the intestines, which can cause diarrhea and/or abdominal pain.
  • Perianal fistula: The most common type of fistula, characterized by an abnormal connection between the skin and anus.

The last local complication of Crohn’s disease is an increased risk of colon cancer, also known as colorectal cancer (CRC). People with Crohn’s disease should start CRC screening with a colonoscopy 8 to 10 years after diagnosis. In comparison, people at average risk for CRC should start CRC screening with colonoscopy at age 50.

Systemic Complications

Complications of Crohn’s disease that manifest outside the intestines are known as systemic complications. These may affect various body systems and areas, and can include:

  • Arthritis
  • Erythema nodosum
  • Pyoderma gangrenosum
  • Skin tags
  • Osteoporosis
  • Episcleritis
  • Scleritis
  • Uveitis
  • Kidney stones
  • Fatty liver disease
  • Gallstones
  • Hepatitis
  • Pancreatitis

In addition, children with Crohn’s disease may experience specific systemic complications such as growth failure and delayed puberty.


At present, there is no known cure for Crohn’s disease, and the primary aim of treatment is to reduce the inflammation associated with it. By doing so, it is possible to alleviate symptoms, achieve long-term remission, and limit the associated complications, all of which can lead to a better long-term prognosis for the patient.


Several classes of drugs can be utilized for the management of Crohn’s disease.

Anti-Inflammatory Drugs
Anti-inflammatory drugs are the first class of drugs used to treat Crohn’s disease since it is a chronic inflammatory condition. Prednisone and budesonide are the main steroids used for treating Crohn’s disease, but they should only be used for short courses of three to four months due to their potential side effects such as weight gain, cataracts, diabetes, high blood pressure, and osteoporosis. The two main oral 5-aminosalicylate (5-ASA) drugs, sulfasalazine (Azulfidine) and mesalamine (Asacol), are of limited value in the treatment of Crohn’s disease.

Immunosuppressant Drugs
Immunosuppressant drugs are another class of drugs used to manage Crohn’s disease, targeting the immune system cells that produce pro-inflammatory substances. This class of drugs is often used in combination with 5-ASA drugs. Common immunosuppressants include azathioprine (Imuran), cyclosporine (Neoral), 6-mercaptopurine, tacrolimus (Prograf), and methotrexate (Rheumatrex), but the most common side effects include increased susceptibility to infection, diarrhea, nausea, and vomiting.

Biologics are a new class of drugs used to treat Crohn’s disease and are reserved for patients who are non-responsive to steroids, 5-ASA drugs, and immunosuppressants. The most commonly used drugs in this class block tumor necrosis factor (TNF), an inflammation-promoting protein. Infliximab (Remicade) and adalimumab (Humira) are the classic anti-TNF drugs. Natalizumab (Tysabri) and vedolizumab (Entyvio) are examples of drugs that target integrin, another inflammation-promoting protein.

Antibiotics are also used to treat Crohn’s disease, specifically for the infectious complications of the disease such as fistulas, abscesses, and perianal disease. Commonly prescribed antibiotics for Crohn’s disease include metronidazole (Flagyl) and ciprofloxacin (Cipro).

Other Medications
Other medications used in the treatment of Crohn’s disease, depending on the symptom or complication, may include anti-diarrheals (Imodium A-D, diphenoxylate with atropine (Lomotil)), iron supplements, vitamin B12 injections, and calcium and vitamin D supplements.


Sometimes, surgery is the final option or required urgently to address the complications associated with Crohn’s disease. It is estimated that between 66 to 75 percent of individuals with Crohn’s disease will need one or more surgeries in their lifetime.

The following surgeries are options for treating Crohn’s disease:

  • Colectomy to eliminate damaged portions of the colon;
  • Proctocolectomy to remove the colon and rectum, which typically necessitates the creation of an ostomy, and;
  • Strictureplasty to repair strictures caused by chronic inflammation.

Living with Crohn’s Disease

Managing Crohn’s disease, a chronic medical condition, involves various measures to improve the outcome of the disease. Apart from following your doctor’s prescription, there are several things you can do:

Exercise and Diet
Regular exercise can help alleviate the symptoms of Crohn’s disease. Experts recommend exercising for at least 30 minutes most days of the week. Additionally, watching your diet is crucial since Crohn’s can affect nutrient absorption. A well-balanced diet, rich in nutrients, can help prevent complications.

Quit Smoking and Drinking
Smoking exacerbates the severity of Crohn’s disease, making it necessary to quit smoking as soon as possible. Drinking alcohol can worsen Crohn’s symptoms since it is an intestinal irritant. Abstaining from alcohol can help prevent flare-ups.

Keep Vaccinations Up to Date
Since some Crohn’s disease treatments can reduce the body’s immunity, making you susceptible to infections, it is essential to keep up to date with your vaccinations. Consult your doctor for recommended vaccinations for influenza, pneumonia, and shingles.

Manage Stress Levels
Excessive stress can cause flare-ups in Crohn’s disease, and therefore stress management is crucial. You can manage stress through regular exercise, meditation, yoga, massages, or pursuing your hobbies and interests. Additionally, pay attention to your mood, and consider joining a support group or seeing a therapist.

Early diagnosis and treatment are crucial in managing Crohn’s disease symptoms and preventing complications. Effective management of the disease can improve your quality of life, reduce the need for surgery, and prevent the development of complications.