Consecutive children hospitalized for an episode of acute ASC, defined as a PUCAI > 65. All patients were treated according to the 2011 ECCO-ESPGHAN guidelines for ASC: all patients received intravenous (iv) corticosteroids (methylprednisolone 1.5-2 mg/Kg/day) for 5 days. Patients not responding to corticosteroids (i.e. PUCAI>65 at day 5) started Infliximab (IFX, 5 mg/Kg 0,2,6 then every 8 weeks) as second-line therapy. All therapies were decided at the discretion of the referral gastroenterologist and recorded on standardized case report forms. A follow-up of 2 years for the colectomy risk was evaluated for all patients.

Clinical assessment through PUCAI and laboratory data (Erythrocyte Sedimentation Rate, C-Reactive Protein, hemoglobin, albumin, hematocrit, ferritin) were recorded at admission and at day 3 and 5. All patients were treated according to the 2011 ECCO-ESPGHAN guidelines for ASC: all patients received intravenous (iv) corticosteroids (methylprednisolone 1.5-2 mg/Kg/day) for 5 days. Patients not responding to corticosteroids (i.e. PUCAI>65 at day 5) started Infliximab (IFX, 5 mg/Kg 0,2,6 then every 8 weeks) as second-line therapy. All therapies were decided at the discretion of the referral gastroenterologist and recorded on standardized case report forms

The surgical need will be evaluated in the group of patients treated with IFX during a 24-month follow-up

Clinical variables at the diagnosis of ASC (i.e. duration of the disease before the episode of SC, past and ongoing therapies, age, family history, Perinuclear Anti-Neutrophil Cytoplasmic Antibodies - pANCA, PUCAI) were evaluated in the group of children needed colectomy at follow-up versus those not requiring surgery.