All pediatric patients ≤ 18 years old and at the Wolfson Medical Center pediatric IBD center who enter clinical remission are routinely assessed by colposcopy or sigmoidoscopy assess. This is an analysis of prospectively collected data regarding PUCAI and endoscopic Mayo score at the time of assessment of mucosal healing by endoscopy. Patients could be included if they have establish ulcerative colitis, while they are on remission or possible remission according to their global assessment. For this study, complete clinical remission was absence of abdominal pain, and no diarrhea or bleeding. Possible clinical remission was defined as only one mild symptom such as: 1.occasional mild bleeding without diarrhea, 2.partially formed stools without blood, or abdominal pain without bleeding or diarrhea.