Crohns disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea (which may be bloody if inflammation is severe), fever, abdominal distension, and weight loss. Complications outside of the gastrointestinal tract may include anemia, skin rashes, arthritis, inflammation of the eye, and fatigue. The skin rashes may be due to infections as well as pyoderma gangrenosum or erythema nodosum. Bowel obstruction may occur as a complication of chronic inflammation, and those with the disease are at greater risk of colon cancer and small bowel cancer.While the precise causes of Crohns disease (CD) are unknown, it is believed to be caused by a combination of environmental, immune, and bacterial factors in genetically susceptible individuals. It results in a chronic inflammatory disorder, in which the bodys immune system defends the gastrointestinal tract, possibly targeting microbial antigens. While Crohns is an immune-related disease, it does not appear to be an autoimmune disease (in that the immune system is not being triggered by the body itself). The exact underlying immune problem is not clear; however, it may be an immunodeficiency state.About half of the overall risk is related to genetics, with more than 70 genes having been found to be involved. Tobacco smokers are twice as likely to develop Crohns disease as nonsmokers. It also often begins after gastroenteritis. Diagnosis is based on a number of findings, including biopsy and appearance of the bowel wall, medical imaging, and description of the disease.
Ostomy-related complications
Common complications of an ostomy (a common surgery in Crohns disease) are: Mucosal edema, Peristomal dermatitis, Retraction, Ostomy prolapse, Mucosal/skin detachment, Hematoma, Necrosis, Parastomal hernia, and Stenosis. Etiology
The etiology of Crohns disease is unknown. Many theories have been disputed, with four main theories hypothesized to be the primary mechanism of Crohns disease. In autoimmune diseases, antibodies and T lymphocytes are the primary mode of inflammation. These cells and bodies are part of the adaptive immune system, or the part of the immune system that learns to fight foreign bodies when first identified. Autoinflammatory diseases are diseases where the innate immune system, or the immune system we are genetically coded with, is designed to attack our own cells. Crohns disease likely has involvement of both the adaptive and innate immune systems. Autoinflammatory theory
Crohns disease can be described as a multifactorial autoinflammatory disease. The etiopathogenesis of Crohns disease is still unknown. In any event, a loss of the regulatory capacity of the immune apparatus would be implicated in the onset of the disease. In this respect interestingly enough, as for Blaus disease (a monogenic autoinflammatory disease), the NOD2 gene mutations have been linked to Crohns disease. However, in Crohns disease, NOD2 mutations act as a risk factor, being more common among Crohns disease patients than the background population, while in Blaus disease NOD2 mutations are linked directly to this syndrome, as it is an autosomal-dominant disease.