Obstruction is possible in any part of the intestinal canal from the mouth to the rectum. The condition is an uncommon one, and when existing it is rarely recognized in time but is mistaken for some other disease of the the bowels.

Causation

It may arise from many causes; more prominent among them are foreign bodies such as bones, wood, grass and other indigestible materials taken into the stomach; obstinate constipation, fecal masses becoming lodged in the bowels; pressure upon the intestines from without, as in cases of tumors, or the abdominal organs greatly enlarged by disease; solid growths within the intestine; the imprisonment of the bowel in holes, Assures and hernial rings; strangulation by false ligaments, or bands of lymph; twisting, and the formation of knots in the intestine; obstruction by the bowel itself as in intussusception, a condition where one portion of the intestine falls into another and becomes strangulated.

Symptoms

The selection of a typical case of acute internal strangulation for an illustration can alone convey an adequate idea of the symptoms.

Pain is usually the first manifestation sufficient to attract attention, although in some instances an insignificant diarrhoea or constipation may have previously existed. The pain is severe, colicky in character and recurs at intervals; the symptoms at this stage are identically those described in colic, for which obstruction is commonly mistaken and treated.

For convenience it is presumed the usual domestic remedies have been employed, and under the impression a free passage of the bowels would bring relief, not only a cathartic but an injection has been administered. But success does not attend the use of these remedies; the bowels do not move, or at least only slightly, the pain persists in all its intensity, and vomiting becomes frequent. The abdomen becomes distended, the expression piteous and anxious, the eyes congested and sunken. The respiration is superficial and frequent, the pulse small and rapid. The animal makes frequent attempts to empty the bowels; these efforts are painful and increased by the failure to purge. The vomited matter is composed, first, of the contents of the stomach and then of greenish matter, later a dirty green, then brownish having something the appearance of diarrhoeal discharges; finally if life is prolonged, matter which should naturally have been thrown off by the bowels appears mingled with that vomited, accompanied with the characteristic fecal odor At this time the animal is in a condition of collapse, the skin cold and clammy, vomiting frequent, breathing rapid, thirst great, pain exhausting, eyes leaden, tongue dry and covered with a dirty brown coat, pulse thin and thready soon is no longer felt, and the animal dies.

This is a picture of a typical case of intestinal obstruction running an acute course. It will be appreciated that few cases have symptomatic phenomena in common. In many instances they run a course which might not improperly be termed chronic; the symptoms then are vague and ill defined. This is commonly the case when the obstruction is due to the impaction of foreign bodies such as woody fibres, bones, etc.

Some cases of the so called chronic affection have been reported throughout which aside from discomfort, loss ot appetite, obstinate constipation, and some fever late in the attack, no positive symptoms were present absolutely indicative of the trouble.

Diagnosis

The diagnosis is usually made at the autopsy, not before. Where the attack takes on an acute course, it might be mistaken for a case of poisoning, more especially with arsenic; but a careful consideration of the symptoms should obviate the danger of confusion. Generally the difficulty in diagnosis will be to discriminate obstruction from colic and acute peritonitis. The persistency of pain, the appearance of tenderness and vomiting, with such marked constitutional symptoms will soon point to a graver affection than colic.

In acute peritonitis the symptoms develop more gradually; the tenderness is more diffused over the whole abdomen, the muscles of which are more rigid, and the matter vomited is different in character. It should also be remembered that peritonitis more commonly follows traumatic injuries and an absence of such a history would weigh considerably.

In obstruction often a lump or tumor appears in the abdomen, showing the locality of the stoppage. At best a diagnosis will be difficult; the considerations noted will aid some in differentiation.

Prognosis

If the obstruction is caused by obstinate constipation and impaction of foreign bodies, the chances of recovery are greater. When the intestine is closed by a twist it might straighten itself, a knot might loosen, a strangulated loop might become free, and an intussusception become disengaged; again that portion of the intestine which may have invaginated or entered into another, might slough off and pass out by the bowels. Such happy results are however very rare, and a fatal termination in the majority of cases may be anticipated.

Treatment

Theory suggests many methods of treatment; experience tells how futile they have proved. The indications are to secure as near perfect rest of the intestinal canal as possible, to relieve pain and support the powers of life. Cathartics must never be given, as they interfere with the objects just mentioned and are deadly in their effect. Opium should be given in sufficient quantity to control the pain, and the strength should be maintained by concentrated and nutritious food with stimulants if needed.