Crohn Disease

Crohn disease is a chronic inflammatory bowel disease (IBD) distinct from ulcerative colitis, often presenting with subtle or nonspecific symptoms. Crohn disease is an immunologically mediated gastrointestinal disorder characterized by transmural inflammation that can involve any segment of the gastrointestinal tract. Population-based studies from Northern Europe and Minnesota report ileal, ileocolonic, and colonic involvement in roughly equal proportions, with disease migration occurring in only 6% to 14% of patients. Pathology limited to the upper gastrointestinal tract, ileum, or ileocolonic region is associated with a higher risk of stricturing and fistulizing complications than isolated colonic involvement. Minnesota data indicate that 19% of patients present with stricturing or fistulizing disease within 90 days of diagnosis, and approximately 50% develop complications such as fistulae, phlegmons, strictures, or abscesses within 20 years. Extraintestinal manifestations may involve the eyes, skin, liver, and joints. The disease follows a chronic, progressive course. Diarrhea, abdominal pain, nausea, and vomiting are common, while weight loss, fever, and fatigue reflect systemic inflammation. Without timely intervention, persistent inflammation can result in disabling complications. Early diagnosis and evidence-based management are essential to optimize long-term outcomes and preserve quality of life.