There is a need for an easily prepared radiopharmaceutical agent for the detection of inflammation and infection. In a group of 14 patients with inflammatory bowel disease (IBD), the detection of actively involved intestinal segments by nonspecific human polyclonal immunoglobulin (IgG) labeled with 99mT~ was compared with that of "'In granulocytes. To determine the specificity of 9RT~-IgG scintigraphy, 8 control patients without clinical indications of intestinal inflammation were examined. gPmTc-IgG was found in the left colon in 8 and in the right colon in 7 of the 8 controls 4 hours after the injection. At that time of scintigraphy only 4 IBD patients exhibited a more intense accumulation at the site of the intestinal segments with active disease. In contrast, in a randomized comparison with "'In granulocytes scintigraphy was-positive in 1 1 patients with the latter technique. Moreover, fewer diseased segments were seen in the 4 patients with positive %"' Tc-IgG scintigraphy (6 versus 12 with "'In granulocytes). In view of the low sensitivity and specificity, it is concluded that 99"Tc-IgG is not suitable for the scintigraphic staging of IBD patients.