Crohn's disease is an inflammatory disease of the intestines that mayaffect any part of the gastrointestinal tract from anus to mouth, causing a widevariety of symptoms.It primarily causes abdominal pain, diarrhea (whichmay be bloody), vomiting,or weightloss, but may also cause complications outside of the gastrointestinaltract such as skin rashes, arthritis andinflammation ofthe eye.
Crohn's disease is an autoimmune disease, in which the body's immunesystem attacks the gastrointestinal tract, causing inflammation;it is classified as a type of inflammatory bowel disease.
Many people with Crohn's disease have symptoms for years prior to thediagnosis. The usual onset is between 15 and 30 years of age but can occur atany age. Because of the 'patchy' nature of the gastrointestinal disease and thedepth of tissue involvement, initial symptoms can be vaguer than with ulcerativecolitis. People with Crohn's disease will go through periods of flare-ups andremission.
Abdominal pain may be the initial symptom of Crohn's disease. It is oftenaccompanied by diarrhea, especially in those who have had surgery. The diarrheamay or may not be bloody. The nature of the diarrhea in Crohn's disease dependson the part of the small intestine or colon that is involved. Ileitis typicallyresults in large-volume watery feces. Colitis may result in a smaller volume offeces of higher frequency. Fecal consistency may range from solid to watery. Insevere cases, an individual may have more than 20 bowelmovements per day and may need to awaken at night to defecate. Visiblebleeding in the feces is less common in Crohn's disease than in ulcerativecolitis, but may be seen in the setting of Crohn's colitis. Bloody bowelmovements are typically intermittent, and may be bright or dark red in colour.In the setting of severe Crohn's colitis, bleeding may be copious. Flatulenceand bloating may also add to the intestinal discomfort.
Symptoms caused by intestinal stenosis are also common in Crohn'sdisease. Abdominal pain is often most severe in areas of the bowel withstenoses. In the setting of severe stenosis, vomiting and nausea may indicatethe beginnings of small bowel obstruction. Although the association is greaterin the context of ulcerative colitis, Crohn's disease may also beassociated with primary sclerosing cholangitis, atype of inflammation of the bile ducts.
Perianal discomfort may also be prominent in Crohn's disease. Itchiness orpain around the anusmay be suggestive of inflammation, fistulization or abscess aroundthe anal area or anal fissure. Perianal skin tags arealso common in Crohn's disease. Fecal incontinence may accompany peri-analCrohn's disease. At the opposite end of the gastrointestinal tract, the mouthmay be affected by non-healing sores (aphthousulcers). Rarely, the esophagus, and stomach may beinvolved in Crohn's disease. These can cause symptoms including difficultyswallowing (dysphagia),upper abdominal pain, and vomiting.
Crohn's disease, like many other chronic, inflammatory diseases, can causea variety of systemic symptoms. Among children, growthfailure is common. Many children are first diagnosed with Crohn's diseasebased on inability to maintain growth. As Crohn's diseasemay manifest at the time of the growth spurt in puberty, up to30% of children with Crohn's disease may have retardation of growth. Fever mayalso be present, though fevers greater than 38.5 ˚C (101.3 ˚F) areuncommon unless there is a complication such as an abscess. Amongolder individuals, Crohn's disease may manifest as weight loss. This is usuallyrelated to decreased food intake, since individuals with intestinal symptomsfrom Crohn's disease often feel better when they do not eat and might losetheir appetite. People with extensive smallintestine disease may also have malabsorptionof carbohydratesor lipids, whichcan further exacerbate weight loss.