Just wanting some advice on what to do with my situation.

My son is 5 years old and bleeding from his rectum and has severe pain, I rushed him to the ER about 2 weeks ago and they did tests and scans and nothing showed. I have had 2 opinions done and both have said the same thing that there is nothing physically wrong with him that he is just wanting attention, I can see he is in pain but no one believes us.

Any advice on what to do or what this could be???