Should I take my son to the doctors? Two days ago my 20month old son got his toes hurt bad we took him to the ER and he had a procedure called repair nail bed foot on two toes on his right foot he now has to wear a cast going up his whole leg and foot but

It. It sounds like he had some sort of procedure for a toenail on 2 toes, if I'm reading your question correctly (help us help you by using punctuation). If this is correct, bleeding is normal, and they should have warned you about it. But now, at 2 days, there shouldn't be any new blood. If he's currently bleeding, then my answer is yes, take him back to the er. If it's old, dry blood on the bandage, there is no need to panic. But I assume you have a follow-up appointment to check on this in the next few days, right?
Cast whole leg? Was there a fracture? Get your doctors advice as to how long the cast should stay on. The wound will need to be inspected as well.
Follow up. You should always follow up as recommended by the er. If you've misplaced the information on the recommendation of outpatient follow up, you can all the hospital for the information.