Clinical presentation of Crohn's, ulcerative colitis, and indeterminate colitis: Symptoms, extraintestinal manifestations, and disease phenotypes.

The incidence of inflammatory bowel disease (IBD) is rising with 25% of IBD diagnosed in children under 18 years of age. The clinical presentation of IBD in children is often vague leading to initial misdiagnosis as infectious colitis or irritable bowel syndrome. When IBD is identified, overlap in histologic and endoscopic features may lead to difficulty distinguishing Crohn's disease from ulcerative colitis, resulting in a higher frequency of the diagnosis indeterminate colitis or IBD unspecified. Recognizing the common and the atypical presentation of pediatric IBD and extraintestinal manifestations will aid in expeditious referral and early diagnosis. Activity severity scoring tools and more specific classification systems for pediatric IBD direct therapeutic algorithms and allow for improved longitudinal assessment since disease severity and location have been shown to be associated with outcome.