342 MORBID ALTERATIONS IN DIGESTIVE ACTIVITY. 



a nitrogenous residue, probably derived from desquamated epithelium, mucus, 

 salts of biliary acids and some fat. Gall-stones may cause obstruction of the 

 bile-ducts and then give rise to symptoms of cholemia. Smaller stones, impacted 

 in the ducts, may cause intense pain (biliary colic) and, by means of their sharp 

 edges, they may even bring about fatal rupture of the ducts. The formation of 

 biliary calculi is probably due ultimately to local stagnation and decomposition 

 of bile in the gall-bladder, caused, for example, by tight lacing, in consequence of 

 which kinking of the gall-bladder takes place. Cholemia and jaundice have 

 already been discussed. 



In the presence of high fever the pancreatic secretion appears to be dimin- 

 ished and its activity enfeebled. Cessation of secretion is attended with the 

 appearance of fat in the form of globules and crystalline fatty acids in the feces. 

 Degeneration of the pancreas may cause diabetes. 



Among the disturbances in the activity of the intestinal tract, constipation 

 (obstipation) is first to be considered. The causes of this condition may reside in: 



(1) Obstructions that occlude the normal passage. In this category belong 

 constrictions of the intestinal canal, due to cicatricial strictures, as, for example, 

 in the colon often after dysentery; neoplasms; further, axial torsion of a loop of 

 intestine (volvulus), or invagination of one portion into another (intussuscep- 

 tion) , or into a hernial sac (hernia) ; also the pressure of tumors or exudates from 

 without. Finally, congenital absence of the anus may constitute the cause. 



(2) Excessive dryness of the intestinal contents may cause obstipation. Under 

 such circumstances the following factors may be operative: Excessive dryness 

 of the food; further, diminution of the digestive juices, as, for example, of the 

 bile in cases of icterus ; or in consequence of great loss of fluid through other organs 

 of the body, as after profuse perspiration or secretion of milk, or, finally, during 

 fever. (3) Derangement of the activity of the muscles and of the motor nerve- 

 apparatus of the intestine may induce constipation through insufficient peristal- 

 sis. This is caused especially by paralytic conditions, as in the presence of in- 

 flammation, degeneration, chronic catarrh and peritonitis. Spinal paralysis is 

 generally attended with sluggish defecation; central affections often also. 

 Whether the phenomena of mental impairment and hypochondriasis are the ac- 

 companiment or the sequel of constipation has not yet been demonstrated. 

 Spasmodic contraction of certain portions of the intestine may give rise to transi- 

 tory retention of the intestinal contents, with great pain (colic) ; as may also spasm 

 of the anal sphincter, which may also take place reflexly, from irritation of the 

 lower portion of the intestine. The feces are almost always hard and deficient _in 

 water, when constipation exists, because during their long sojourn in the in- 

 testines fluid is absorbed from them. In consequence, the fecal masses form large 

 pieces (scybala) within the large intestine and these may, in turn, constitute a 

 new obstacle to the onward movement (coprostasis) . Diminution in the intes- 

 tinal and gastric secretion occurs also as a sign of general nervous affections (hys- 

 teria, hypochondria, mental disorders), although increased secretion may also 

 take place under such circumstances. 



The agents that cause constipation are, in part, those that paralyze the motor 

 apparatus temporarily, such as opium or morphin; and, in part, those that dimin- 

 ish the secretions of the intestinal mucous membrane, and exert a constringent 

 effect upon the blood-vessels and the mucous membrane, such as tannic acid, 

 alum, lime, lead acetate, argentic and bismuth nitrates. 



Increase in the intestinal discharges is usually accompanied by a greater 

 degree of fluidity of the feces (diarrhea). The causes are as follows: 



1. Unduly rapid propulsion of the contents through the intestinal canal, 

 particularly through the large intestine, so that absorption from this part cannot 

 take place in a normal manner. The increased peristalsis is due to irritation of 

 the motor-nerve apparatus of the intestine, and is principally reflex in character, 

 Rapid passage of the ingesta through the intestinal canal results in the presence 

 in the discharges of substances that could not be completely or at all digested 

 in the short time afforded (lientery) . This will also occur if portions of the in- 

 testine, situated high up, communicate with lower portions of the intestine, 

 through abnormal openings. 



2 . The feces may be of the consistency of paste from the admixture of water, 

 mucus and fat, in considerable amount; further, from the residue of fruits and 

 vegetables. In rare cases in which the feces contain a good deal of mucus, so- 

 called Charcot's crystals are present (Fig 92, c). In the presence of ulceration 

 of the intestine, leukocytes (pus-cells) are found. 



