Exclusion criteria for patients
hernia, ileostomyChronic renal failure, necrosis
NECROSIS

American Society of Anesthesiologist (ASA) physical status class ≥ 4Infected/septic surgical site (risk for surgical site occurrences (SSO) of grade 4 according to Ventral Hernia Working Group (VHWG) classification) (see Supplement Presence of parastomal hernia in loop ileostomy site with fascia defect > 8cm (Table Presence of a concomitant incisional hernia that impedes loop ileostomy reversal or placement of the mesh at the ileostomy site (Table Patients with prior mesh placement on site of ileostomyChronic renal failure under haemodialysis/peritoneal dialysisPatients under strong immunosuppression or other medications likely to impede wound healing as judged by the operating surgeon. Examples of strong immunosuppression are:Steroid therapy ≥ 10 mg/dayTherapy with antitumor necrosis factor α (anti-TNF-α) within the last 4 weeksTherapy with everolimus or sirolimus within the last 4 weeksTherapy Avastin within the last 4 weeksCongenital haemorrhagic diathesis with need of perioperative treatmentParticipation in another interventional trial with interference on intervention and primary outcome of this trialDetails of exclusion criteria 3 and 4Presence of a parastomal hernia or incisional hernia on clinical exam, but  - Parastomal hernia is smaller or larger than 8 cm - Or if unclear whether incisional hernia impedes loop ileostomy reversal or placement of the mesh at the ileostomy site