<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been experiencing some strange symptoms lately, including retention of urine, chills, nausea, and rectal bleeding. Can you help me figure out whats going on?  <response>: Based on your symptoms, it sounds like you may be experiencing ischemia of the bowel. It is a serious condition where the blood flow to the intestines is reduced or blocked, and it can cause these symptoms as well as severe abdominal pain. We need to do some tests to confirm the diagnosis ASAP. 