The diagnosis must deal with the following three points: A. Recognition of the intestinal obstruction. B. Its seat. C. Its etiological factor.

The recognition of an acute intestinal obstruction is not difficult if the symptoms described above are present in a marked degree. Thus total absence of passage of fecal matter and flatus combined with symptoms of collapse, meteorism, pains, and fecal vomiting will permit a positive diagnosis of intestinal obstruction. In many instances, however, only a few of the symptoms mentioned are present, and then the diagnosis is quite difficult. The symptom of the greatest diagnostic value is fecal vomiting, although even this alone does not always warrant the diagnosis of obstruction, for it also occurs in intestinal paralysis. The latter condition must be especially borne in mind in cases in which there has been a history either of contusion of the abdomen or of a reposition of incarcerated hernia shortly before the appearance of the disease. The fecal vomiting of hysterics can also be easily recognized, as there are always symptoms present which indicate the true condition.

The greatest difficulty in diagnosis lies in the differentiation between intestinal obstruction and diffuse peritonitis, especially if the latter accompanies appendicitis. All the symptoms characteristic of intestinal obstruction may occur also in peritonitis. A thorough consideration of all the symptoms and their differentiation in these two diseases will, however, permit a decision.

The following points will serve as a guide in this connection: In acute peritonitis there is a rise of temperature at the beginning of the disease, while in intestinal obstruction there is at first no fever or even a subnormal temperature. There are exceptions, however, and a general peritonitis of a grave nature may run its course without any fever but with symptoms of collapse. The pains on pressure over the abdomen are much more intense in peritonitis; in intestinal occlusion the spontaneous pain may occasionally even be relieved by pressure. Fecal vomiting is of comparatively rare occurrence in peritonitis, and if present it usually appears later than in intestinal obstruction. The me-teorism is diffuse in peritonitis right from the start. It thus causes a general distention of the abdominal parietes. In obstruction the accumulation of gas is at first less pronounced, circumscribed, and increases gradually. In peritonitis the abdomen becomes tense from the first, while in obstruction, at the commencement at least, it is as a rule soft. The existence of an exudation speaks in favor of general peritonitis. In peritonitis accompanying appendicitis there will be besides the above symptoms the phenomena characteristic of the latter disease.

In some instances, however, the differentiation between peritonitis and obstruction will hardly be possible and mistakes are liable to occur.

Acute intestinal obstruction is occasionally simulated by poisoning with arsenic and also by a very severe attack of cholera. In the former condition there will be a history of poisoning, and in the latter the presence of cholera bacilli in the dejecta will clear up the diagnosis. In rare instances a severe attack of biliary colic or of renal colic may in some respects resemble intestinal obstruction. A thorough examination, however, will always reveal the true condition. In biliary colic as a rule there is swelling of the liver and sometimes jaundice; in renal colic the pains radiate from the kidney to the bladder, there is a burning sensation during urination, and the urine often contains mucus and occasionally a few pus corpuscles or blood cells. Intestinal colic resulting from chronic lead poisoning occa-. sionally simulates true obstruction of the bowels. The anamnesis, however, will show that we have to deal with lead poisoning. Besides, in these cases there is, as a rule, a more or less sunken condition of the abdomen.

Simple intestinal colic (of nervous origin) will hardly ever give rise to mistakes in the diagnosis, as the clinical picture is less severe and the disease quickly subsides.