CHANGES IN INTESTINES. THE FECES. 2O/ 



is difficult of digestion. This is readily shown with cornmeal. 

 and other products containing much cellulose. On the other 

 hand with fine, well-sifted flours in which the starch granules 

 are easily turned into paste by boiling or baking, the utiliza- 

 tion of the starch is usually much more complete. For the 

 identification of starch several methods have been applied, 

 some direct, others indirect. 



The recognition of starch by the microscope usually fails, as the outline 

 of the granules is destroyed by the process of cooking. When the cooking 

 has been imperfect, however, the granules may be intact and in a condition 

 suitable for identification. The iodine test is frequently satisfactory. 

 For this the feces are boiled with water and filtered. In the filtrate the 

 iodine solution is added as for other tests. To facilitate the separation of 

 the starch from cell structures a little hydrochloric acid may be added to 

 the boiling water. 



The amount of starch is best determined after conversion into sugar. 

 This may be accomplished by prolonged heating with a little hydrochloric 

 acid, which changes the starch into glucose. This may be measured by 

 one of the copper reduction processes, but not without some difficulty as 

 the solution is always highly colored. The necessary precautions can not 

 be given here. 



The normal starch content of the feces is always small, but 

 in disorders of digestion, especially with diminished activity 

 of the pancreas, more starch may be found. In very young 

 children the consumption of starchy foods is very often fol- 

 lowed by the appearance of starch in the feces. 



Sugar. The presence of traces of sugar in the normal feces 

 has been frequently affirmed and as often denied. The larger 

 part of the more recent evidence on the question goes to show 

 that sugar is not normally present even in traces. All forms 

 of sugar are very soluble and easily absorbed from the intes- 

 tine. The ability of sugar to escape absorption through the 

 whole length of the intestinal tract would therefore appear 

 very problematical. Even in disease sugar is of rare occur- 

 rence in the feces as far as has been determined by experiment. 

 But the detection of traces is not an easy task. 



Pathologically sugar seems to pass through the intestine and 

 escape with the feces only when the conditions for absorption 



