Where do all the tablets go?

Barium sulphate tablets, identical in size and shape to those of aspirin, were given to 98 consecutive patients during routine radiological studies of the upper gastrointestinal tract. In 57 patients the tablets remained in the oesophagus for longer than five minutes. Delay in passage of the tablets was particularly likely to occur in patients with hiatus hernia and reflux and if defects of peristalsis in the oesophagus were observed.