What should i do? is it something to be concerned about?

There's a possibility i have celiac disease. and i ate bread today but not much so i ddnt think it wud do anything. over the last few hours ive had the urge to make a bowel movement (sorry for description) a lot more than normal and i have a stiffness feeling everywhere between my ribs to my hips that comes and goes. im really scared but i pierced my belly on myself and havent told my parents. so i dont want to tell them about my stomach because theyll yell about my belly on. what should i do? im so scared