1.A group of 60 patients, infested with Chilomastix mesnili only, has been studied. Also 267 patients infested with Giardia lamblia and 420 control subjects in which parasites were not found after at least three examinations of stools have been studied.
2.From the standpoint of geographic distribution, our records indicate that Chilomastix mesnili is perhaps more common in the South Atlantic states than in other portions of the United States. The distribution of Giardia lamblia is general throughout the United States.
3.Giardia lamblia is more common in children than in adults.
4.In each one of these groups of cases, diarrhea, either intermittent or steady, is of practically equal occurrence; this is true also of the incidence of constipation and of normal stools. Bloody diarrhea is perhaps less common in cases of infestation with Giardia lamblia than in the control cases.
5.Achlorhydria, although often found correlated with diarrhea, does not in itself explain the diarrhea.
6.After thorough study of these groups, diarrhea is probably most often explainable on the basis of improper food or infection with certain bacteria or perhaps some as yet unknown abnormal physiologic state. These possible causes are materially strengthened by the self-limitation of the symptoms in many cases, and by the ability to relieve most of these patients by proper food and general hygienic measures.
7.Scientific proof is lacking for maintaining that intestinal flagellates cause diarrhea.