Suggest Treatment For Choking On Food Particle

My son has had a past choking expierience about 3 yrs ago in which he choked on a peice of steak, it did not block his passage way but would not come unlodged and needed to be taken to the er to get it removed. He now has swallowed a simple spaghetti noodle which he felt was stuck in his throat and now feels it may be in his lung, not in pain but feels uncomfortable