Crohn’s Disease

What is Crohn’s disease?

Crohn’s disease is a type of inflammatory bowel disease (IBD). It is estimated that over half a million Americans are living with Crohn’s disease. Crohn’s disease and ulcerative colitis are the two most common types of IBD.

Crohn’s disease can affect any part of the gastrointestinal tract, but it usually affects the small intestine and the beginning of the large intestine. The inflammation caused by Crohn’s disease often spreads deep into the layers of affected bowel tissue and can be very painful.

The exact cause of Crohn’s disease is unknown, but it is thought to result from an autoimmune reaction, where the immune system mistakenly attacks the GI tract. Genetic and environmental factors may trigger this reaction. Symptoms include:

  • Stomach pain
  • Severe diarrhea
  • Malnutrition
  • Weight loss
  • Fatigue

Complications can include bowel obstruction, ulcers, fistulas (abnormal connections between body parts), abscesses, and an increased risk of colon cancer.

Treatment typically involves anti-inflammatory drugs to reduce inflammation and control symptoms. In some cases, surgery may be necessary to remove damaged portions of the digestive tract. The goal is to reduce symptoms, maintain remission, and improve quality of life.

What causes Crohn’s disease?

The exact cause of Crohn’s disease is not fully understood. It likely results from a combination of factors:

  • Immune system dysfunction, where the immune system attacks gut cells or overreacts to normal gut bacteria
  • Genetic factors, as those with a family history are at higher risk
  • Environmental factors, such as:
    • Smoking, which worsens disease course
    • Diet and lifestyle influences
    • Changes in gut bacteria
    • Use of nonsteroidal anti-inflammatory medications (NSAIDs)
    • Possible infection triggers

Multiple factors likely combine to cause Crohn’s disease in any given person.

What are the common symptoms of Crohn’s disease?

Symptoms vary by severity and location of inflammation. Common symptoms include:

  • Abdominal pain and cramping, often in the lower right abdomen
  • Diarrhea, sometimes bloody
  • Fatigue and low energy
  • Malnutrition and nutrient deficiencies
  • Weight loss
  • Fever in severe cases
  • Mouth sores
  • Perianal disease, causing pain or drainage around the anus
  • Reduced appetite

Extraintestinal complications may include:

  • Joint pain and swelling
  • Skin conditions
  • Eye inflammation
  • Osteoporosis

Symptoms can flare and then remit; early diagnosis and treatment improve outcomes.

How is Crohn’s disease diagnosed?

Diagnosis involves clinical evaluation, laboratory tests, imaging, and endoscopy:

  • Medical history and physical exam
  • Blood tests for inflammation markers (CBC, CRP, ESR)
  • Stool tests to rule out infections and detect inflammatory markers (calprotectin, lactoferrin)
  • Endoscopic procedures:
    • Colonoscopy with biopsies to inspect the colon and ileum
    • Upper endoscopy for the esophagus, stomach, and duodenum
  • Imaging:
    • CT scan to assess inflammation and complications
    • MRI to identify fistulas and abscesses
    • Capsule endoscopy for small-bowel visualization

These tests confirm inflammation, define its location and extent, and guide treatment.

How is Crohn’s disease treated?

Treatment aims to reduce inflammation, relieve symptoms, prevent flares, and manage complications. Options include:

  • Medications:
    • Steroids (e.g., prednisone, budesonide) for short-term inflammation control
    • Immunomodulators (e.g., azathioprine, mercaptopurine, methotrexate)
    • Biologics (e.g., TNF inhibitors, integrin inhibitors, interleukin inhibitors)
    • Antibiotics (e.g., ciprofloxacin, metronidazole) for fistulas and abscesses
  • Diet and nutrition management, including special diets or supplemental nutrition
  • Surgery, such as resection, stricturoplasty, or fistula repair; often required in up to half of patients
  • Lifestyle changes:
    • Smoking cessation
    • Stress management (exercise, yoga, meditation)
  • Regular monitoring with blood tests, imaging, and endoscopies to adjust therapy

What are the complications of Crohn’s disease?

  • Bowel obstruction from strictures
  • Ulcers anywhere in the digestive tract
  • Fistulas between intestines, organs, or skin
  • Abscesses and potentially life-threatening infections
  • Anal fissures and rectal bleeding
  • Malnutrition and anemia
  • Increased risk of colon cancer
  • Skin disorders such as hidradenitis suppurativa
  • Other health issues: osteoporosis, arthritis, liver or gallbladder disease
  • Medication risks: immune suppression leading to infections or increased cancer risk
  • Blood clots in arteries and veins

Sources

  • Overview of Crohn’s disease. Crohn’s & Colitis Foundation. Accessed Apr. 12, 2024.
  • Sandborn WJ. Crohn’s disease evaluation and treatment: clinical decision tool. Gastroenterology. 2014;147(3):702-705. PMID:25046160. Accessed Apr. 12, 2024.
  • Crohn’s Disease. National Institute of Diabetes and Digestive and Kidney Diseases. Accessed Apr. 12, 2024.
  • Crohn’s Disease. Medscape. Accessed Apr. 12, 2024.