The methods ordinarily adopted for the determination of the motility of the gastro-intestinal tract are:
The ingested barium meal. By following roentgenologically the progress of this radiopaque mixture, it is possible to determine, at any time, the exact position of the head and of the tail of the column of barium. Unquestionably, this is the most accurate method we can employ for this purpose at the present time.
The use of powdered charcoal or carmin. This material is not radiopaque, and its progress cannot be followed fluoroscopically. At best, only the terminal result can be noted, namely, the time of the appearance of the carmin or charcoal in the stool. No information as to the intermediate progress is obtainable. The method, however, in addition to giving us information as to the total gastro-intestinal motility, serves as a means of demarcation. When it is desired to study the nature of the
Buckstein J. THE CELLULOID CAPSULE: A MEANS OF DETERMINING THE MOTILITY OF THE GASTRO-INTESTINAL TRACT. JAMA. 1923;80(9):621. doi:10.1001/jama.1923.26430360002009a