Only small amounts of barium are used and the images are further improved if air is "pumped" into the area being examined. This distends the organ and spreads the baruim thinly and evenly over the surface of the bowel lining. This procedure is then sometimes known as "double contrast" or "air contrast". Barium studies can be divided into 4 separate groups which outline different parts of the digestive system as detailed below:

1. Barium Swallow: barium is swallowed and the act of swallowing is either pictured or filmed to produce moving pictures. This is useful to identify abnormalities in the swallowing process or structural problems. It will also reveal problems with the oesophagus (food pipe) which leads down to the stomach.

2. Barium Meal: barium is swallowed and allowed to go down into the stomach and X-rays are then taken. Diagnoses such as hiatus hernia, gastric ulcers and other abnormalities can then be detected.

3. Barium Meal & Follow Through: this is similar to barium meals but the barium travels further down through the stomach and into the small intestines.

4. Barium Enema: barium is inserted through the anus and travels up through the rectum into the colon (large bowel). This is usually requested if there is blood passing through the bowel or if there has been a change in bowel habit, such as diarrhoea or constipation. A special diet is usually followed for 48 hours before the test and a laxative used to ensure the bowel is clear. This enables the barium to spread further and evenly to give better quality films. Although not painful, patients may feel some discomfort and feelings of fullness.