The tissue distribution of intravenously injected native and enzyme-treated human gammaglobulin has been investigated in human rectum mucosa. FITC-labelled antibodies to human gammaglobulin were used to locate the injected antibody preparation. Three hours after application of these different gammaglobulin-preparations no enrichment in the mucosa was found. Neither the native gammaglobulin nor the enzyme-treated gammaglobulin showed any concentration in the lamina propria of the large bowel mucosa or an intracellular enrichment in the epithel. This study shows that the quicker elimination of enzyme-treated gamma-globulin from the circulation cannot be explained by an intracellular increase.