What procedure involves a series of x-rays to examine the gastrointestinal (GI) tract?

The procedure that involves a series of x-rays to examine the gastrointestinal (GI) tract is known as barium studies. This diagnostic method utilizes barium sulfate, a contrast material that enhances the visibility of the GI tract on x-ray images. When a patient ingests or is given barium rectally, it coats the lining of the esophagus, stomach, and intestines. This coating allows for better visualization during the x-ray, helping healthcare providers identify issues such as tumors, ulcers, blockages, or abnormalities in motility.

In contrast, a colonoscopy is a direct visualization procedure involving a flexible camera inserted through the rectum to examine the colon, rather than using x-rays. Esophagoscopy also employs a scope to visually inspect the esophagus, focusing specifically on that area rather than the overall GI tract. Preventative surgery involves surgical interventions taken to reduce cancer risk but does not relate to imaging or x-ray procedures at all. Thus, barium studies stand out as the correct option for examining the GI tract through a series of x-ray images.