INFECTIONS OF THE DIGESTIVE TRACT 263 



flatulence, and an increase of the indican in the urine. 

 The explanation of this is to be sought in the fact that 

 the cathartic causes the passage of native proteids and 

 possibly of peptones from the small into the large intes- 

 tine, where it is possible to attack the former if anaerobes 

 be present. Presumably in persons harboring few an- 

 aerobic bacteria this effect would be slight, but in per- 

 sons in whom organisms of the class of B. putrificus or 

 B. aerogenes capsulatus are abundant one would expect 

 the appearance of considerable indican in the urine. 



The influence of constipation upon the development of 

 indicanuria is very different in different persons. Most 

 children and many adults may go without a movement 

 for several days and still fail to develop indicanuria if 

 this has previously been absent. There are other per- 

 sons in whom constipation is followed by a marked 

 increase in the output of indican. A wholly satisfactory 

 explanation of this difference in the influence of constipa- 

 tion upon indol formation in the intestine is not at pres- 

 ent possible. Sufficient bacteriological data are lacking. 

 A probable explanation is the following. The formation 

 of indol in the intestinal tract depends on the decomposi- 

 tion of proteids through the activity of microorganisms. 

 If the colon bacilli have for any reason ascended in large 

 numbers above their usual upper limit, namely the 

 ileum, into the jejunum or duodenum, they will act 

 there upon peptones formed in the course of the normal 

 digestion of proteids. From such peptones they will 

 make indol. Under these circumstances the aid of putre- 

 factive anaerobes is not necessary for the production of 



