Some girls may start menstruating as early as age 10, but others may not get their first period until they are 15 years old. The amount of time between a girl's periods is called her menstrual cycle (the cycle is counted from the start of one period to the start of the next). Some girls will find that their menstrual cycle lasts 28 days, whereas others might have a 24-day cycle, a 30-day cycle, or even longer.
A barium swallow is a special type of X-ray test that helps your doctor take a close look at the back of your mouth and throat, known as the pharynx, and the tube that extends from the back of the tongue down to the stomach, known as the esophagus.
The barium sulfate used in a barium swallow is a non-radioactive contrast agent that will help your doctor and radiologist to better see the outline of your throat and esophagus. The addition of the barium to your swallow allows the normal x-ray to visualize soft tissue that is normally invisible.