During diagnostic testing, a patient swallows a barium sulfate contrast; fluoroscopy follows its movement through the esophagus, stomach, and small intestine. What is this study called?

• A. Endoscopy
• B. Upper GI Series (Barium Swallow)
• C. Colonoscopy
• D. Sigmoidoscopy

Answer: (B)

The test relies on radiographic imaging with a contrast agent to visualize the path of the upper GI tract. When a patient swallows barium sulfate, the liquid coats the lining of the esophagus, stomach, and into the small intestine, and real-time X-ray fluoroscopy tracks its movement. This combination—oral contrast plus live imaging of the esophagus, stomach, and duodenum—is the upper GI series (often called a barium swallow). It reveals the shape, position, and motility of the upper GI structures, helping identify strictures, ulcers, hernias, reflux, or other abnormalities.

Endoscopy, by contrast, uses a flexible camera inserted through the mouth to directly view the mucosa, rather than outlining the lumen on X-ray. Colonoscopy and sigmoidoscopy visualize the colon with an endoscope, not the upper GI tract with radiographs.