My son will be 12 in May.  Today he was feeling fine, then around 330 I stopped and bought him McDonalds then around 9:00 he stared complaining of sharp pains in abdomen that would come and go frequently. He took a hot bath and it seemed to give him some relief.  He went to bed and woke up within halfhour wit pain and ran to bathroom.  He is still in pain.  He is laying down.  He has no fever.  I was concerned if the symptoms of appendisitis similar or the same as if you ate something that was bad.  Also can appendisitis just flare up in a matter of hours, from no symptoms to severe pain In abdomen  from center to right side.
Hi and thank you so much for this query. I am sorry to hear about this pain that your child is experiencing. If the intensity is that concerning, my advice would be that you get him to the emergency room for proper examination and management. It could be appendicitis and the symptoms often start suddenly. Though I really lack more information to suggest this is the possible cause because this diagnosis is mainly made from physical examination. I hope this helps. I wish him well. Courage as you actively look for solutions to this.