Background: The conventional goal of treatment in Crohn’s disease is to induce and maintain clinical remission. However achieving clinical remission alone may not change natural history of Crohn’s disease. Emerging evidence suggest that achieving and maintaining mucosal healing is associated with more sustained clinical remission and reduced rate of hospitalisation and surgery. The aim of our study is to identify the mucosal healing status of patients with Crohn’s disease on long term maintenance treatment. Methods: We have prospectively assessed the endoscopic severity of Crohn’s disease in children who had undergone reassessment colonoscopy from October 2012 to September 2013. We have used Crohn’s Disease Endoscopic Index of Severity (CDEIS) for children who did not have bowel resection and Rutgeerts endoscopic grading scale for children who had right hemicolectomy. Results: 59 colonoscopic examinations were done in 57 children in the time period from October 2012 to September 2013. In 51 children, we have used CDEIS to assess mucosal healing. 20 children had achieved complete mucosal healing (CDEIS score 2). 31 children did not achieve complete mucosal healing and their CDEIS score varied from 3 to 25. Significantly higher proportion of children in the complete mucosal healing group had received treatment with anti-Tumour Necrosis Factor (anti TNF) agents compared to the children in the other group (65% v 32% p value0.04). The anti TNF agents used in the children in both groups were Infliximab. There were no significant difference in disease distribution, peri-anal involvement, Haemoglobin, CRP, ESR, platelets and Azathioprine use when comparing children in both the groups. Hospitalisation rate was higher for children who have not achieved complete mucosal healing (35% v 10%). No children needed surgery in the group with complete mucosal healing compared to 5 children needing right hemicolectomy in the group with incomplete mucosal healing. Seven children had reassessment colonoscopy after their right hemicolectomy and we have used Rutgeerts endoscopic grading scale to assess their mucosal healing status. 4 children had complete mucosal healing (Rutgeerts score i0), 3 were on treatment with Infliximab and Azathioprine, one was on Azathioprine alone. Conclusions: In our experience 42% (24/57) children with Crohn’s disease on maintenance treatment have achieved complete mucosal healing. Treatment with Anti TNF agents was a significant factor in achieving mucosal healing. Children who had achieved complete mucosal healing did not need bowel surgery. P407 Mucosal healing during the clinical remission in patients with ulcerative colitis A. Atanassova1 *, I. Kotzev2, P. Genev3, V. Velikova4. 1Medical University, Gastroenterology, Varna, Bulgaria, 2Medical University Varna, Gastroenterology, Varna, Bulgaria, 3Medical University Varna, Patology, Varna, Bulgaria, 4University of Economics, Department of Statistics, Varna, Bulgaria