This condition is characterized by an inflammatory process concentrated unevenly throughout the entire thickness of any portion of the gastrointestinal (GI) tract from the mouth to the anus. However, the ileum and right colon are most often involved. The focus and extent of the inflammation, and its potential for proximal gastrointestinal tract involvement distinguish Crohn's disease from ulcerative colitis.

The cause of Chron's disease is unknown. Although genetic, biochemical and immunologic patterns have been recognized in patients, a definitive pathophysiological etiology has not been established.

Signs and symptoms of Crohn's disease are determined by the site and extent of inflammation. Gastroduodenal Crohn's disease mimics peptic ulcer disease, with nausea, vomiting, and epigastric pain. If the small intestines are involved, the patient experiences cramping, diarrhea, and abdominal tenderness. Abdominal tenderness is most often due to transmural inflammation. Transmural inflammation leads to fibrosis and narrowing of the intestinal lumen, producing symptoms of obstruction; nausea, vomiting and waves of abdominal pain, and a reduced output of stool. When the colon is involved, abdominal pain, cramping or localized pain, rectal bleeding, and diarrhea occur. Weight loss is common, and is related to malabsorption or decreased intake of food. Other systemic symptoms include fever, night sweats, malaise, and arthralgias.

When Crohn's disease is suspected endoscopy and x-ray studies of the abdomen are done. Histologic studies of biopsy specimens are also completed to confirm the diagnosis. Ultrasound studies or computed tomography (CT) scans may also be done to clarify the extent of disease.

Treatment depends on the extent and severity of intestinal involvement. Unlike ulcerative colitis, Crohn's disease is not cured by surgery; however, surgery may be used to reduce complications. The condition is managed with medications, such as anti-inflammatory drugs, antibiotics, and immunosuppressives. Nutritional therapies are also employed in the treatment of Crohn's disease, and in the prevention of its complications. A low residue diet, or a diet consisting of solutions containing a combination of basic food substances to sustain life (elemental feedings) are used to reduce symptoms.

Periodic remissions and exacerbations are common. Disease-free periods may extend for years or decades after surgery. However, fifty percent of those that receive an operation require a second operation, and fifty percent of those that receive a second require a third. The tendency for recurrence may have psychosocial implications. The quality of life is low, and may also be related to uncertainties regarding recurrence. The chance of developing intestinal cancer increases with the length of survival time.

None.