Guest blogger pediatrician Dr. Gwenn says you shouldn't give kids snacks in your pediatrician's waiting room.

Have you ever wondered why doctor's offices sometimes have signs that read "No Eating or Drinking Allowed"? It's not just because we don't want to clean up your kid's Ritz cracker crumbs. Here are three good reasons:

1. We don't want other kids to get sick.
In the child health world, we worry a great deal about kids with food allergies. Food you eat can place allergic kids at risk for serious reactions if they come into contact with even a tiny crumb. Making waiting areas and exam rooms food-free is the only way to protect these kids.

2. We can't examine your child's mouth very well if it is coated with freshly eaten food.
The food gets caked all over the teeth and the soft tissues, and hides all the things we need to see. Short of really brushing the teeth and rinsing, those food particles stick like glue.

3. Food or liquids can make some symptoms worse.
Many kids come to us with gastrointestinal complaints: stomachaches, vomiting, nausea, diarrhea. Those symptoms typically worsen with food or liquid, so we prefer kids hold off until we've had a chance to do our exam and make some suggestions for advancing your child's diet. If your child is very thirsty, talk to the nursing staff to see if a few sips of a clear liquid is acceptable while you are waiting for the pediatrician.

Next time you're at the pediatrician's office, please pay attention to the signs and realize they are there for good reason. And leave the Cheerios at home.

For more from Dr. Gwenn, click here.