Conversation: The conversation between human and AI assistant.
[|Human|] My father has stage IV prostate cancer. He has a colostomy and ileostomy done two months ago. He is at the end of his life and is very weak. We found that he has a urine infection and he is being given antibiotic. In his condition he is passing blood in his stools. The stools are very dark almost black with blood mixed. What do I need to know about this development? Does it indicate that his condition has taken a turn for the worse?
[|AI|]  Good evening. Blood in stool which is black indicates bleeding from esophagus or stomach. Check for his platelet counts. An upper GI endoscopy for stomach and esophagus can be done to see for the source of bleeding and management accordingly. Also check whether he is taking any iron supplement as it can also change the color of stool. It may or may not indicate that his condition is worsening due to cancer, but it needs evaluation.