Evidence that barium sulfate, administered by enema as a contrast medium for roentgenologic study of the colon, actually enters the lumens of the intestinal glands was obtained in the case of a 24-year-old man. That this was not the result of individual peculiarities or of local disease was shown by further studies in five unselected female patients, for biopsy showed barium sulfate crystals within some of the intestinal glands after a barium enema in each case. It was also found that pathological changes followed. This suggests that in the production of barium granulomas the barium enters through the lumens of the intestinal glands.
Sasson L. ENTRANCE OF BARIUM INTO INTESTINAL GLANDS DURING BARIUM ENEMA. JAMA. 1960;173(4):343–345. doi:10.1001/jama.1960.03020220017004