Critical Micellar Concentration

Definition Typical presentation of Crohn disease includes inflammation in the terminal ileum. However, this typical presentation with ileitis is seen only in 70% of cases. 25% of patients present with disease confined only to the colon (Crohn colitis) and in 5% exclusive involvement of the upper gastrointestinal tract is seen. The diagnosis is mostly based on a suggestive clinical course, a typical distribution of affected areas throughout the gastrointestinal tract (“skip lesions”) and a typical type of endoscopic lesions (Fig. 1). Histological characteristics (i.e. granuloma formation) are only seen in a minority of the patients.