Hernia at the site of stoma closure occurs in up to 30% of patients and is associated with adverse effects on quality of life. In up to 10% of cases, patients are submitted to complex re-operation which carries significant morbidity. Not all patients will report symptoms or undergo repair, as they do not wish to have a further major operation. Incisional hernias at the site of stomas closure form an important and well defined subgroup. If there is a measurable benefit from mesh insertion, elective use of a collagen mesh would warrant consideration in the closure of other difficult, contaminated abdominal wounds. This study will also provide useful information on the value of using a CT scan as an early diagnostic tool of herniation, which could then be used in future abdominal wall studies as a surrogate endpoint for clinical hernia.