This study evaluated the effects of total colectomy on the biodistribution of technetium-99m pertechnetate ((99m)TcO(4)(-)) on the 28th postoperative day in rats. Samples of several organs were harvested for counting the percent of injected radioactivity/g of tissue (%ATI/g). The %ATI/g in colectomy rats was higher in the stomach and ileum than in sham and controls (p<0.05). Increase in mucosa and muscularis size of ileum was observed. Colectomy was associated with lower biodistribution in bladder and thyroid, T3, and T4, than in controls. Copyright 2010 Elsevier Ltd. All rights reserved.