Colonic manifestations of runt disease.

In view of the severe wasting and diarrhea in animals with runt disease, it is remarkable how little the intestinal tract of these animals has been studied. Observers have noted in the small bowel atrophy of Peyer's patches,"' slightly increased numbers of leucocytes in the mucosa`' and clubbing and bridging of villi in the ileum.' Thymectomized rats with runt disease have developed ulceration of the small bowel mucosa,4 but no lesions have been described in the colons of these animals, possibly in large part because they have not been sought. The present study, therefore, was planned to evaluate any lesions that might appear in the colon of rats with runt disease.