Upper GI series, small bowel follow-through and contrast studies of the digestive tract

An upper GI series (barium swallow and meal) is an X-ray examination of the oesophagus, stomach and first part of the small intestine (duodenum), carried out while you drink a liquid that shows up on X-rays. The radiologist follows its passage live on a screen. Depending on the question, the liquid is barium (a thick white liquid) or a water-soluble iodinated contrast agent, especially to check a suture after stomach surgery (for example weight-loss surgery) or when a leak is suspected. A pharyngo-oesophageal study looks more closely at swallowing; the upper GI series may be extended to the small intestine, or a small bowel follow-through may be done on its own. Today, gastroscopy and CT scans answer many questions, but contrast studies remain useful for assessing the movement and shape of the organs.