don't worry about what other people say it will not matter what they said later in life if it's what makes you happy then keep it. It's your choice not there's and i'm sure they would not like it if they got made fun of for something like this.
F--- those people. Seriously, nothing gets me more aggravated than people being complete a-holes to someone with a disability. One day they will see the flaws in their actions but do not let someone else's pathetic attempts to hurt your feelings affect you in any way shape or form. Live your life to the fullest and ignore those pathetic excuses for people.
You can't really do anything but ignore it I'm sorry to say. It's a medical condition. Do your best to ignore these insensitive bullies. If you are in school perhaps you and your teacher or nurse can use you condition as a teaching / learning session. Most people are scared when they don't know about something. Turn things around and teach them. Maybe you could get some of the worst offenders to act whatever way your illness works. They might be surprised at how hard it is for you to do normal things they take for granted. If you are physically bullied let the teacher, principal and your parents know. Perhaps a visit to the worst bullies' homes with your parents might help.