THE FRONTIERS OF MEDICINE 



swallow their food, owing to nervous manifestations which 

 produce no definite visible change in the esophagus or in 

 the stomach. 



There are still many unexplained conditions involving 

 the stomach which demand further research for their 

 solution. There are instances in which the stomach fails 

 to supply the proper secretions, and the reasons for this 

 failure are unknown. Apparently the tissues of the stomach 

 may be made to yield extracts essential to health and to 

 life, such as the extract that controls pernicious anemia. 

 Here is a new field for intensive research. 



The procedures that apply to the study of the stomach 

 apply also to the study of the intestines. Only recently 

 has it become possible to pass a tube through the stomach 

 and into the intestines in order to withdraw their secretions 

 for investigation. Only recently have methods been devised 

 for determining the rate at which food moves along the 

 intestines, for studying the bacteria that live there nor- 

 mally and abnormally, and for observing the obstructions, 

 paralyses, and many other disturbances which manifest 

 themselves by serious symptoms. 



There are forms of constipation which are due to inter- 

 ference with the digestion in the intestine, other forms 

 which are due to disturbance of the motility in the intes- 

 tine, and some forms which are merely the results of bad 

 habits. There are situations in which it is exceedingly 

 dangerous to eat food with too high an amount of rough- 

 age, and situations in which an increase in roughage 

 provides the conditions necessary for a successful cure. 



Within the past twenty-five years methods have been 

 developed for changing the nature of the intestinal flora. 

 MetchnikofF's original idea that the Bacillus bulgarkus was 

 the normal inhabitant and that its presence was synonym- 

 ous with long life has been changed to emphasis on another 

 germ called the B. acidophilus. Attempts to implant the 



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