Endoscopic evaluation after surgery in inflammatory bowel disease

We read with interest the Review by Bo Shen and colleagues regarding endoscopic evaluation of surgically altered bowel in inflammatory bowel disease.1 We commend the authors for using the Oxford Centre for Evidence-Based Medicine methodology, a rigorous and widely accepted standard for evaluating evidence. However, there are several recommendations in the ileal pouch section for which there is no level 1 (randomised controlled trials), 2 (cohort studies), 3 (case-control studies), or 4 (case-series, or poor quality cohort or case-control studies) evidence.