Randomization and blinding
The study was designed as a randomized non-inferior feasibility trial, with 1:1 randomization allocation. Eligible patients were randomized to undergo loop-ileostomy closure with either synthetic light-weight mesh or BM in retrorectus space. Separate randomization lists were generated for each study center. Patients were allocated to study groups according to a computer-generated list, compiled by a biostatistician not involved in the clinical care of trial patients. Randomization was performed in blocks, where block size varied randomly between two, four and six. The randomization group was disclosed in the patient hospital records, and therefore blinding of the personnel and the patient could not be guaranteed during the follow-up.