Different types of barium X-ray examination are used to investigate different parts of the gastrointestinal tract. Barium swallow involves drinking a barium solution and is used to investigate the oesophagus. A barium meal is carried out to look at the lower oesophagus, stomach, and duodenum. Barium followthrough is used to investigate disorders of the small intestine; X-rays are taken at intervals as the barium reaches the intestine. A barium enema is used to investigate disorders of the large intestine and rectum; barium is introduced though a tube inserted in the rectum. Barium remaining in the intestine may cause constipation. Therefore, it is important to have a high-fibre diet and drink plenty of water after a barium examination, until all the barium has passed through.... barium x-ray examinations