Crohn’s Disease

What is Crohn’s Disease? Crohn’s disease is a chronic inflammatory bowel disease (IBD) that results in severe digestive symptoms. Symptoms most often begin between the ages of 15-25 years and affects 96.3 to 315.5 per 100,000 people in the Unites States. Men and women are affected equally. Crohn’s disease has historically more prevalent in western countries and urban populations, however, the worldwide incidence of the disease is increasing.

What causes Crohn’s Disease?

The pathophysiology of Crohn’s disease is thought to be the consequence of the interaction of multifactorial contributors.

  • Genetics- Crohn’s disease is thought to follow a polygenic inheritance pattern, with over 100,000 genes implicated in the possible development of the disease. First degree relatives of affected individuals have a 7% risk and are more likely to develop Crohn’s disease at an earlier age.
  • Alterations to the microbiome– Increased levels of enterobacteria in the gut and higher titers of E.Coli have been associated with the development of Crohn’s disease.
  • Immune dysfunction– An increased immune response is implicated in the development of Crohn’s disease, but it is unknown if it plays a part in the initial onset of the disease, or occurs due to environmental insults or altered gut microbiome.
  • Environmental factors– Several environmental risk factors have been associated with Crohn’s disease, including smoking, oral contraceptive use, urban environment, antibiotic use, and frequent use of NSAIDs.

Signs and Symptoms of Crohn’s Disease

Like the other IBD, ulcerative colitis, the major symptoms of Crohn’s disease include diarrhea, abdominal cramping, bleeding, and weight loss, although bleeding is less common in Crohn’s disease. Symptoms of Crohn’s disease are variable and can range from mild to severe and life threatening.

Characteristic unique to Crohn’s disease include:

  • Development in any area of the digestive tract, most frequently in the ileum and colon. 
  • Transmural involvement.
  • Development of fistulas and rectal lesions.
  • Malnutrition.
  • Presence of skip lesions, cobblestoning, ulcerations, and strictures observable in colonoscopy.

Source: Cushing, K., & Higgins, P. D. R. (2021). Management of Crohn Disease. JAMA, 325(1), 69.