Extreme IBS pain. tell me how to stop it!?

it keeps on coming in waves and wont stop. i pooped (yeah tmi, i know) and it still wont go away. i mean these are pains that make me scream and make me breathless laying on the floor. i get naseau when i have the pains but dont puke. donttell me to go to the hospital. ive done that before and they just shove water up my butt. i take miralax daily and drink at least one bottle of water per day. im 14 and i dont think its my appendics