Adolescent Adult Age Distribution Behcet Syndrome--diagnosis Biopsy, Needle Capsule Endoscopy--methods Case-Control Studies Colonic Diseases--diagnosis Colonoscopy--methods Endoscopy, Gastrointestinal--methods Female Humans Ileal Diseases--diagnosis Immunohistochemistry Incidence Intestinal Mucosa--pathology Male Middle Aged Probability Reference Values Risk Assessment Severity of Illness Index Sex Distribution Ulcer--diagnosis Young Adult