Establishing that mucosal healing (MH) has occurred after therapy is an important treatment goal, and the gold standard is endoscopic evaluation. In UC it is unclear if clinical parameters are adequate. The pediatric ulcerative colitis activity index (PUCAI) has demonstrated good correlations for clinical remission and disease severity, but its role for establishing mucosal healing after therapy has not been validated . The ability to predict mucosal healing may be different for patients in long term remission compared to assessment after obtaining clinical remission. No previous study has prospectively validated the use of PUCAI as a proxy for MH specifically during clinical remission after therapy.

All pediatric patients ≤ 19 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 for at least 3 months after treatment of flare. For this study, complete clinical remission was absence of abdominal pain, and no diarrhea or bleeding (PUCAI<10). sigmoidoscopy will be performed between 12-24 weeks after remission was documented.

Inclusion Criteria:

1. Ulcerative Colitis patient

2. clinical remission (PUCAI<10) for at least 3 months.

3. Sigmoidoscopy for assessment mucusa healing after therapy performed between 12-24 weeks after remission was documented

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Patients could be included if they have establish ulcerative colitis, while they are on clinical remission