Abstract-Across the medical literature, delayed diagnosis and treatment leads to more costly and worse outcomes. Rehabilitation patients, especially those with polytrauma, often have a complex mixture of medical, social, and psychological health problems that can impair effective diagnosis and treatment. The case presentation describes the procession toward the diagnosis of ulcerative colitis in a preinjury asymptomatic male, suggesting a potential mechanism for its emergence and describing the effect of delayed diagnosis on the efficiency of rehabilitative care. As such, the differential diagnosis for early posttraumatic diarrhea should remain broad, particularly if unexplained or ineffectively controlled.