When to Seek Medical Care

If you suspect that you or your child might have pinworms, you should make an appointment to see your doctor.

To help the doctor make the diagnosis, look for these signs:

• Pinworms are big enough to be seen with the naked eye. They are yellow-white and look like a fine piece of thread. They are usually less than one-half inch long.

• Pinworms are most active at night. The best time to see them on the anus is a few hours after bedtime. Parents sometimes try to sneak up on the worms by throwing back the child's bedcovers and shining a flashlight on a bare bottom in hopes of catching the culprits in action.

• Pinworms can also sometimes be seen on the outside of a child's stool.