This case report presents a 77-year-old female with dementia and hypertension who experienced reduced consciousness during hydrotherapy. She was found to have hypotension, a low Glasgow Coma Scale score, and right thigh pain. Blood work showed acute kidney injury and elevated inflammatory markers, while imaging revealed surgical emphysema in the right thigh and pelvis without trauma. Necrotizing fasciitis was ruled out, but anaerobic cultures identified Bacteroides fragilis, suggesting non-clostridial gas gangrene from a suspected colonic perforation. Due to clinical instability and comorbidities, surgical intervention was not feasible. Despite antibiotics and supportive care, her condition deteriorated, and she transitioned to palliative care. This case highlights the diagnostic challenges in complex elderly presentations.