BackgroundRestorative proctocolectomy (RPC) is performed using a variety of staged procedures for several diseases. Our aim was to assess whether the severity of complications, classified according to Clavien–Dindo, was related to the diagnosis or the procedure. MethodsA consecutive series of children receiving an ileoanal pouch was prospectively recorded. Complications were scored by two blinded observers. Major complications were Clavien–Dindo ≥3b. Procedures were classified as: colectomy, proctectomy and pouch or proctocolectomy and pouch. Diagnoses were classified as: ulcerative colitis, familial adenomatous polyposis or other: idiopathic constipation, total colonic Hirschsprung’s disease, juvenile polyposis, Crohn’s colitis, fibrosing colonopathy or necrotising enterocolitis. Results128 children underwent 191 procedures: 61 colectomies, 63 proctectomies and 67 proctocolectomies. 84 children had ulcerative colitis, 20 had FAP and 24 had other indications. Major complications were significantly more likely with proctocolectomy (16/67, 24%) than with either colectomy (4/61, 7%) or proctectomy (8/63, 13%), p = 0.01. There was no association between diagnosis and major complications: ulcerative colitis (18/133, 14%), FAP (5/20, 25%), other (5/38, 13%) p = 0.4. There was no increase in major complications following proctectomy if a major complication had occurred during prior colectomy. Overall, 15% of procedures experienced a major complication. 6/9 stoma related complications required operative intervention. ConclusionsThe severity of complications after RPC in children is related to use of a two stage rather than three stage sequence of surgery, not the underlying diagnosis. Type of studyCase control study. Level of evidenceLevel III.