My daughter just sent me this. I know they shave that area sometimes and they do program on her left side so having feces slide down on this isn't good. It is hard to tell from pictures but it looks more like skin irritation of some kind than a pressure sore to me. She is going to sleep on her belly tonight and make the appointment on campus tomorrow.
Last year she had a nasty sacral sore that resulted in a flap surgery. She called understandably upset. (She is away at college.)