The relief from chronic constipation and diarrhea by the ingestion of milk fermented with Bacillus acidophilus is a phenomenon worthy of further study.1 The beneficial effects obtained by such therapy might be due to a multiplicity of factors. It has been held that chief among these is the ingestion of an increased volume, and more particularly the addition of considerable water to the daily diet. As against this physical or mechanical interpretation, there is a chemical explanation, based on the presence of a considerable amount of lactic acid, together with the disintegration products of the organism B. acidophilus. Finally, there is the strictly bacteriologic interpretation, which holds the living B. acidophilus organisms responsible for all benefits. The experiments here described, which are still in progress, were devised in the hope of arriving at some definite conclusion regarding this phenomenon.
Patients with a history of chronic constipation were