Previously there have been reported * certain aspects, comparatively short-term, of the effects of supervoltage irradiation on the normal gastrointestinal tract of young male adults, treated for testicular tumor. The present study is more inclusive and definitive in that autopsy findings, follow-up by correspondence, and thorough clinical examinations of approximately 100 patients, five years or more after completion of therapy, are available. In all, approximately 230 records more than five years after therapy have been evaluated. A detailed history, including social, sexual, and economic adjustment after treatment, and physical examination, was made in the clinical study of each available patient. In all of these patients complete gastrointestinal x-rays were obtained. About 25 patients had cholecystograms. In many of the patients gastroscopy preceded by gastric biopsy, with use of a technique described by Palmer,6 and sigmoidoscopy were performed. Determination of gastric acidity with a standard histamine dosage (0.5 cc.), liver-function tests