2006 ICD-9-CM Volume 1 Diagnosis Codes Home > Diseases Of The Digestive System 520-579 > Noninfective Enteritis And Colitis 555-558 > 2006 ICD-9-CM Diagnosis 555 Regional enteritis View the most recent version of ICD-9-CM 555 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. 555 is a non-specific code that cannot be used to specify a diagnosis 555 Includes Crohn's disease Granulomatous enteritis 555 Excludes ulcerative colitis (556)