Abdominal pain, d+, loss of appetite, fever and rectal bleeding (bright red) every hour or less now. doc said go back if not gone tmw, should i worry?

Yes: I would consider these symptoms as serious in view of the associated abdominal pain and fever. SImple hemorrhoidal bleeding is unlikely and I am concerned about acute inflammatory bowel disease or an invasive bacterial colitis. If you're experiencing profuse rectal bleeding,continuing fever and abdominal pain, proceed to the hospital emergency room.