What would happen if a suggestion, given under hypnosis, were not removed?
From the tone of the question, we assume you are referring to suggestions not intended for self improvement, which you would want to remain. Let’s assume the hypnotist (and these things would only take place on the level of stage hypnosis) suggested that his subject’s arm is “very heavy and cannot lift up” … or some other such nonsense. If, after the entertainment is finished, the hypnotist forgot to remove the suggestion, there very well could remain some discomfort. The suggestion may very well remain, either in full or partially, and certainly could be uncomfortable until it wore off.