The baseline patient characteristics will be evaluated based on pilot tested data extraction sheets. The assessment will include demographics, clinical data as well as laboratory work up. The Charlson morbidity index, will be used to assess co-morbidity, the Nutritional risk score (NRS) to assess nutrition status and the Harvey-Bradshaw index (HBI) to evaluate the activity of Crohn's disease. The duration of surgical procedure, along with the amount of blood transfused, will be recorded in all patients.