METABOLISM IN THE STOMACH AND INTESTINES 625 



The functions of the intestines are, in general, to complete the pro- 

 cesses of digestion. This it does by carrying along further, the digestion 

 of foodstuft's begun in the stomach. Associated with this, the intestines 

 absorb the various foodstuffs, evacuate indigestible residue, and excrete 

 waste products from the body. For the body metabolism to be normal, 

 these functions must, not be greatly disturbed. There is a certain amount 

 of complementary functioning in the intestines which can carry metab- 

 olism along, if the disturbances are not too marked. 



The functions of the small intestines differ somewhat from those of 

 the large intestines. In the former the larger part of digestion of food- 

 stuffs as well as absorption takes place. Very little absorption takes place 

 in the large intestines and its main function is excretatory. The fer- 

 ments, which by their digestive activity prepare the various foodstuffs 

 for absorption, are largely secreted by the small intestines, in conjunction 

 with the pancreas and liver, and it is in this part of the alimentary tract 

 that the major part of the absorption of foodstuffs takes place. The colon 

 practically plays a passive part in digestion. It absorbs water, but pro- 

 teins and carbohydrates only to a small degree, and no fats. The lower 

 part of the colon is mainly concerned with the excretion of salts and for- 

 eign substances, while the fermentation of carbohydrates is almost limited 

 to this part of the intestinal tract. The intestines differ from the stom- 

 ach in one important aspect, that decomposition normally takes place 

 there. 



The main functions of the intestines are then: secretion, absorption, 

 excretion, decomposition and the mechanical elimination of fecal matter. 

 These various functions are so closely interrelated that it is difficult to 

 trace the part that each plays in intestinal diseases. For example: dis- 

 turbances in "secretion cause disturbances in absorption, while disturb- 

 ances in absorption and secretion cause disturbances in peristalsis. So 

 it is easy to conceive, with these various components of digestion dis- 

 turbed, how difficult it would be to designate which factor is responsible for 

 the effects observed upon the metabolism of the body. Such effects are 

 produced largely through chemical and biological derangements, which 

 influence especially the nutrition of the body. As there are similar chem- 

 ical and biological disturbances in many diseases of the intestines, so the 

 metabolic complications resulting are in many respects similar, differing 

 largely in degree and not in kind, and concerning principally the nutrition 

 of the body. Diseases of the intestines do not cause any specific derange- 

 ment of the metabolism as occurs in diabetes and gout f or ^ instance. Fur- 

 thermore mechanical factors, such as obstruction, the position of tumors, 

 increased peristalsis, etc., play an important role in determining the 

 extent, as well as the rapidity, of the disturbances of the metabolism.^ 



The fact that there is practically no literature on the subject indicates 

 the obscurity in which it is now veiled. This is largely due, no doubt, to 



