A stomach ache once in awhile can be normal, but when you experience persistent abdominal pain, nausea, vomiting or difficulty swallowing, your doctor may send you for an endoscopy.

Dr. Manny Alvarez, senior managing health editor of FoxNews.com, says that although this procedure may seem scary, it is very simple and safe.

An endoscopy is performed by a gastroenterologist using an endoscopea long, thin, flexible tube with a tiny camera attached to its end, which allows your doctor to see inside your stomach on a monitor.

If it sounds intimidating, not to worry—an IV is administered beforehand for pain medication and a sedative—to ensure you will be comfortable and won't feel a thing.

Once sedated, your doctor will gently insert the endoscope through your mouth and slowly move it down the esophagus.

After reaching your stomach, the doctor will be looking for a number of potential problems, including inflammation, infections, ulcers and tumors.

Your doctor may also want a tissue sample for further testing to distinguish between benign and cancerous cells, which can be collected with the endoscope.

It is also used to detect helicobacter pylori, the bacterium that may lead to painful ulcers.
Uncomplicated upper endoscopies should only take 10 to 20 minutes.

Afterward, your throat may be sore, and you may feel a bit bloated, but this is only temporary. But if these symptoms continue, make sure you call your doctor.