Age 16, trouble breathing when laying on right side?

Intestinal issues. See a Pulmonologist first, if the doc said that it is fine then it is your intestine. You are too young to experience intestinal issue. Are you having enough sea salt intake? You need to take up to one tsp a day. At your age you may start with 1.2 tsp. Build up a sweat and taste your perspiration on your upper part of your arm if it is not salty than you are salt deficient.