Crohn’s disease is a type of inflammatory bowel disease (IBD) marked by chronic inflammation in the digestive tract. This condition can affect any part of the gastrointestinal (GI) tract, from the mouth to the anus, and the inflammation can penetrate the bowel’s deeper layers. As a lifelong condition, its symptoms often fluctuate in severity over time.
Symptoms and Complications
Common symptoms of Crohn’s disease include persistent diarrhea, abdominal cramping, and pain, often localized to the lower right abdomen. Many people also experience an urgent need for a bowel movement, rectal bleeding, and a feeling that the bowel has not been completely emptied. Systemic symptoms such as fatigue, fever, weight loss, and a reduced appetite are also reported.
Over time, chronic inflammation can lead to complications. Bowel obstructions (strictures) can occur when the intestinal wall thickens and narrows from scarring. Ulcers may develop anywhere in the digestive tract, including deep tears in the anus called fissures. Another complication is the formation of fistulas, which are abnormal tunnels connecting the intestine to other organs. The disease can also interfere with nutrient absorption, leading to malnutrition and anemia, which in children can delay growth.
Causes and Risk Factors
The precise cause of Crohn’s disease is not identified, but research indicates a combination of factors contributes to it. It is widely believed to involve an abnormal immune system response, where the immune system may mistakenly attack harmless bacteria in the digestive tract. This can lead to chronic inflammation and damage to intestinal tissues.
Genetics play a significant role, as the disease tends to run in families. Between 5% and 20% of people with IBD have a first-degree relative with the condition. Researchers have identified over 200 gene variations that may be involved, but these genetic factors are not solely responsible, suggesting environmental triggers are also involved.
Several risk factors are associated with a higher likelihood of developing Crohn’s disease. The condition is most often diagnosed in adolescents and young adults before age 30. Cigarette smoking is the most significant controllable risk factor and can also worsen its course. Crohn’s is more prevalent in developed countries, urban areas, and among Caucasians, particularly those of Eastern European (Ashkenazi) Jewish descent.
The Diagnosis Process
Confirming a diagnosis of Crohn’s disease involves a multi-step process, as no single test can definitively identify the condition. A physician will begin by reviewing the patient’s symptoms and medical history, followed by a physical examination.
Laboratory tests are a standard part of the workup. Blood tests can reveal signs of inflammation, such as elevated C-reactive protein levels, or anemia from blood loss. Stool studies are used to check for blood or to exclude other causes of symptoms, like bacterial infections.
Imaging procedures are used to visualize the digestive tract and assess the extent of inflammation. A colonoscopy, which examines the large intestine and the end of the small intestine, is one of the most accurate methods for diagnosis and allows for the collection of tissue samples (biopsies). Other procedures may include an upper endoscopy to view the upper GI tract, a capsule endoscopy to see the small intestine, or imaging studies like CT and MRI scans to detect complications such as fistulas or abscesses.
Treatment and Management Strategies
The goal of treating Crohn’s disease is to reduce inflammation, achieve long-term remission, and prevent complications. Treatment strategies are tailored to the individual and combine medication, potential surgery, and lifestyle adjustments.
Medications are a primary tool for management. Anti-inflammatory drugs like corticosteroids are used for short-term control during a flare-up. For long-term management, immune system suppressors or biologics may be prescribed to reduce underlying inflammation. Biologics target specific proteins in the immune response and are effective for moderate to severe cases.
Surgery may become necessary if symptoms are severe or complications arise, with up to three-quarters of individuals requiring a procedure at some point. Procedures can involve removing a diseased bowel segment, repairing fistulas, or correcting obstructions. While it does not cure Crohn’s, it can improve quality of life.
Lifestyle and dietary management also help control symptoms. While diet does not cause Crohn’s, certain foods can aggravate symptoms during a flare-up, and keeping a food diary can help identify triggers. Quitting smoking is strongly recommended as it can worsen the disease and reduce treatment effectiveness.
Distinguishing Crohn’s from Ulcerative Colitis
Crohn’s disease and ulcerative colitis (UC) are the two main types of inflammatory bowel disease (IBD). While they share many symptoms, they are distinct conditions. The primary difference lies in the location and pattern of inflammation. Ulcerative colitis affects only the large intestine (the colon) and rectum, with inflammation occurring in a continuous pattern.
In contrast, the inflammation in Crohn’s appears in patches, with healthy tissue located between inflamed areas. Another distinction is the depth of inflammation. In UC, inflammation is confined to the colon’s innermost lining, which differs from Crohn’s, where deeper inflammation is why complications like strictures and fistulas are more common.