Introduction: The role for diverting ostomy as a method to help reduce morbidity and mortality has been well established in the combat trauma population. However, factors that influence the type of ostomy used and which ostomies become permanent are poorly studied. We examine patterns of ostomy usage and reversal in a large series of combat trauma patients. Methods: We performed a retrospective review of combat casualties treated at our continental U.S. military treatment facility from 2003 to 2015. All patients who underwent ostomy formation were included. Clinical and demographic factors were collected for all patients including the type of ostomy and whether or not ostomy reversal took place. Patients were grouped and analyzed based on ostomy type and by ostomy reversal. Results: We identified 202 patients who had ostomies created. End colostomies were most common (N = 149) followed by loop colostomies (N = 34) and end ileostomies (N = 19). Casualties that underwent damage control laparotomy (DCL) were less likely to have a loop colostomy created (p < 0.001). Ostomy reversal occurred in 89.9% of patients. There was no difference in ostomy reversal rates by ostomy type (p = 0.080). Presence of a pelvic fracture was associated with permanent ostomy (OR = 3.28, p = 0.019), but no factor independently predicted a permanent ostomy on multivariate analysis. Discussion: DCL and a severe perineal injury most strongly influence ostomy type selection. Most patients undergo colostomy reversal, and no factor independently predicted an ostomy being permanent. These findings provide a framework for understanding the issue of fecal diversion in the combat trauma population and inform military surgeons about injury patterns and treatment options.