INVALIDITY OF THE INTRAVENOUS MG-LOAD TEST IN PATIENTS WITH CROHNS-DISEASE OF THE SMALL-BOWEL

Fecal output of soluble Mg was determined in 5 patients with Crohn's d isease and ileal resection and in 5 patients with Crohn's disease conf ined to the ileum and compared with 10 patients with Crohn's disease o f both ileum and colon. The 10 patients with normal colon had a signif icantly greater fecal output of soluble Mg when compared with the 10 p atients with diseased colon. The group with normal colon had a greater fecal output of soluble Mg during the day of the intravenous Mg-load test when compared with the group with diseased colon, while ''retaini ng'' a greater quantity of Mg from the loading dose of Mg. It is sugge sted that the partial loss of Mg in stools invalidates the intravenous Mg-load test in patients with Crohn's disease confined to the small b owel.