2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Digestive System 520-579 > Noninfective Enteritis And Colitis 555-558 > Regional Enteritis 555.* > 2006 ICD-9-CM Diagnosis 555.9 Regional enteritis of unspecified site View the most recent version of ICD-9-CM 555.9 A chronic transmural inflammation that may involve any part of the DIGESTIVE TRACT from MOUTH to ANUS, mostly found in the ILEUM, the CECUM, and the COLON. In Crohn disease, the inflammation, extending through the intestinal wall from the MUCOSA to the serosa, is characteristically asymmetric and segmental. Epithelioid GRANULOMAS may be seen in some patients. Inflammation of the intestines, but usually only of the small intestine. Regional enteritis increases the risk for developing colon cancer. Also called Crohn's disease. A gastrointestinal disorder characterized by chronic inflammation involving all layers of the intestinal wall, noncaseating granulomas affecting the intestinal wall and regional lymph nodes, and transmural fibrosis. Crohn's disease most commonly involves the terminal ileum; the colon is the second most common site of involvement. --2004 Chronic inflammation of the gastrointestinal tract, most commonly the bowel. Crohn's disease increases the risk for colon cancer. 555.9 is a specific code that can be used to specify a diagnosis 555.9 contains 4 index entries View the ICD-9-CM Volume 1 555.* hierarchy Alternate Terminology Crohn's disease NOS Regional enteritis NOS  Index entries containing 555.9: Crohn's disease (see also Enteritis, regional) 555.9 Disease, diseased - see also Syndrome Crohn's (intestine) (see also Enteritis, regional) 555.9 Enteritis (acute) (catarrhal) (choleraic) (chronic) (congestive) (diarrheal) (exudative) (follicular) (hemorrhagic) (infantile) (lienteric) (noninfectious) (perforative) (phlegmonous) (presumed noninfectious) (pseudomembranous) 558.9 regional (of) 555.9 intestine large (bowel, colon, or rectum) 555.1 with small intestine 555.2 small (duodenum, ileum, or jejunum) 555.0 with large intestine 555.2 segmental (see also Enteritis, regional) 555.9