Twenty-nine years ago I gave my first opaque enema under fluoroscopic screen control. The publications of Pfahler and a few references from foreign literature constituted the stimulus for the undertaking. Bismuth subnitrate was the opaque salt, suspended in buttermilk. The chief aim of the study was to determine the position of the transverse colon and of the right and left colic flexures. To emphasize the contrast presented by the elaborate roentgen study of the colon as practiced now, with indications for its use covering a very wide range of pathologic possibilities, I was asked to offer a review of the evolution of the technic of x-ray examination of the colon, followed by an evaluation of the different methods.
Routine practice in intestinal x-ray examinations includes the opaque meal, with appropriate screen or film observations of the opaque residues as they move along the large bowel (fig. 1), followed by the