The use of pills for gastric tests suggested itself in the course of the employment of the duodenal catheter for ascertaining the size of the pylorus in infants. The size of the catheter which can be readily introduced past the pylorus in the newborn as well as in somewhat older infants1—the approximate circumferences of the pylorus at these periods of life—having been ascertained, it seemed that the same information could be obtained more easily through the use of pills having definite circumferences. Accordingly, bismuth pills were prepared of three sizes (9, 15 and 21 mm. in circumference), and coated with many layers of keratin to prevent their dissolution by the gastric juice.
The use of pills has certain advantages over that of a powder suspended in milk, which is the usual way of giving bismuth to infants for radioscopic examination of the stomach. The introduction of the pill