A patient with dysgammaglobulinemia is reported who had hepatosplenomegaly, thrombocytopenia, and roentgenographic demonstration of nodularity of the large bowel subsequently proved to be due to nodular hyperplasia.The intimate relationship of the lymphoid and hematologic systems is discussed in order to explain the possible genesis of these findings, especially of the submucosal lymphoid hyperplasia of the bowel.The roentgenographic findings of our patient are described and discussed relative to differential diagnosis. A barium enema examination and gastrointestinal series should be done as part of an immunologic work-up.Multiple nodular polypoid mucosal lesions of the large bowel may be, as they are in the small intestine, indicative of underlying dysgammaglobulinemia.