The course of an acute obstruction will depend first upon its location, and secondly upon its nature. The higher up in the intestine the obstruction is situated the more rapid as a rule is the course of the disease. Volvulus and strangulation of the intestine are generally accompanied by a more violent course than is obturation by foreign bodies. The duration of the disease is not always the same. In some instances the patient dies very soon, a few hours or a day or two after the commencement of the obstruction, of shock and paralysis of the heart. In other instances the disease lasts several days or even a week. In intussusception the duration of the disease is longer, several weeks, showing periods of exacerbations and remissions.

If the patient recovers from the collapse and there is a spontaneous re-establishment of the patency of the intestinal lumen (i.e., the obstruction is relieved, which may happen in cases of invagination, torsion, and obturation by foreign bodies), there is at first as a rule a passage of flatus, which may be followed by a fecal movement of offensive odor. In case of invagination there is often some blood in the evacuation. All the symptoms which have previously existed begin to abate, the fecal vomiting ceases, the meteorism becomes less, and the patient gradually recovers from his severe illness. In cases in which the intestinal obstruction has led to considerable anatomical changes within the lumen of the bowel (ulcers, gangrenous processes, adhesions), after a period of comparative euphoria, symptoms of chronic intestinal obstruction may develop.

In the greater number of cases of acute intestinal obstruction the latter persists, and the patient, if not operated upon, generally dies of diffuse peritonitis, with or without perforation of the intestines. Even without perforation, peritonitis may readily develop in consequence of the paralytic state of the intestine; for, according to Bon-necken,1 bacteria can easily penetrate the intestinal wall as soon as the latter is in a paralyzed condition and thus give rise to inflammation of the peritoneum.

Circumscribed peritonitis around the occluded part need not give distinct symptoms. General peritonitis, however, always enhances the alarming symptoms already existing. Thus the meteorism increases; the dyspnoea, hiccough, and vomiting become more violent, the pains unendurable; the heart begins to give out and pronounced collapse appears. Generally there is a rise of temperature and frequently a fluid exudation within the abdomen is discoverable. If perforation of the intestine has taken place, the symptoms just described appear still earlier and with more violence. The abdomen becomes more or less rounded and the diaphragm is pushed upward in the highest degree. The liver dulness disappears and the pains become excruciating. The shock may be so great that the patient becomes unconscious and remains so until death brings relief.

Complications appearing during the disease may also be the cause of death. Thus deglutition pneumonia (Schluck-pneumonie) which occasionally occurs by aspiration into the lungs of gastric and intestinal contents during the act of vomiting, or septicaemia in consequence of intestinal perforation, may develop with embolic processes in the lungs, liver, and other organs. In exceptional cases there occurs an adhesion of the occluded intestinal coils to the anterior abdominal wall, and after the gangrenous destruction of the latter as well as of parts of the gut, an anus praeternaturalis develops, or a fistulous opening between two portions of the intestines, or again a fistula of the intestine into the bladder, uterus, vagina, or stomach.

1 Bonnecken: Virchow's Archiv, Bd. 120.