<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been feeling very tired lately and noticed blood in my stool. What could be causing this?  <response>: Based on your symptoms, it is possible that you have Hypergammaglobulinemia, a condition where there is an excess of immunoglobulins in the blood, which can cause fatigue and gastrointestinal bleeding. I will need to run tests to confirm. 