INTESTINAL OBSTRUCTION (ILEUS), in surgery, a condition in which the onward passage of the intestinal contents is prevented. It is often associated with strangulation of the gut, leading to gangrene, and with systemic poisoning due to the absorption of toxins, resulting from the changes in the intestinal wall. The sole availing treatment is surgical, and that at the earliest possible moment. Intestinal obstruction may be con veniently divided into acute and chronic.
(I) Strangulation by Bands or Adhesions or through Apertures. —These bands may result from stretching of inflammatory ad hesions left by a former peritonitis, and are commonly situated between different parts of the mesentery or between the mesentery and another organ such as the appendix. A loop of bowel passes under a short constricting band and cannot return, or if the band is long it may form a noose in which the bowel is strangled (fig.
I.) A coil of intestine may also slip into a hole in the mesentery or omentum or find its way into a pouch of peritoneum, form ing what is known as an internal hernia. The patient is abruptly seized with acute abdominal pain associated with collapse. The pain is usually referred to the um bilicus, but this is no guide to the situation of the lesion. Vomiting is persistent, and starts the earlier as the obstruction is higher in the intestinal tract. Ultimately it becomes faecal. There is no obvious tumour; constipation is present, the abdominal walls are flaccid at first, but if no relief is obtained become tender when peritonitis ensues. In cases not treated by operation the average duration is five to seven days, and death takes place from exhaustion or from toxaemia following peritonitis.
(2) Vo/vu/us is a twisting of the gut usually preceded by chronic constipation. There are two chief varieties: (I) in which the bowel is twisted upon its mesenteric axis (fig. 2) ; (2) in which it is wound round another coil of intestine. The sigmoid flexure is the com monest seat for volvulus. When once present, plastic peritonitis fixes the coil in position and the blood supply becomes obstructed. The acute symptoms start abruptly and are those of internal strangu lation, but the pain at first is more inter mittent in type. There is usually early tenderness over the spot and constipation is absolute. Much distress is occasioned by abdominal distension from flatus, which develops with remarkable rapidity. The swelling is localized at first. Spontaneous natural cure is unknown, and without surgi cal interference death is inevitable.
(3) Acute Intussusception forms about 3o% of all cases of intestinal obstruction, and is the most common variety found in children. More than 50% of the cases are found during the first ten years of life, and half that amount in babies under one year; the large preponderance is in males. By intussusception is meant an invagination or protrusion of a part of the intestine in the lumen of the intestine immediately below it ; the lower part of the intestine may be said to have swallowed that immediately above it. The mesentery attached to the upper portion is necessarily dragged in with it. The condition may be seen by re ferring to the diagram (fig. 3). It is to the constriction of the vessels in the entering mesentery and later to their possible com plete obstruction that are due the late serious phenomena of intussusception, e.g., gangrene or rupture of the gut. Peritonitis also ensues, and by the formation of ad hesions between the serous coats of the entering and returning parts leads to irre ducibility of the intussusception. Spontaneous reduction of the invagination sometimes occurs, but the common result is gangrene with perforation of the intestine and acute septic peritonitis. Occa sionally when there is no perforation adherence takes place be tween the segments, and the gangrenous portion sloughs off and is discharged by the rectum. The cause of intussusception is said to be violent peristaltic action, however produced. Polypoid tumours or masses of worms, or masses of irritating ingesta, are said to lead to its occurrence. X. Dolore and R. Leriche, how ever, contend that the primary factor is congenital mobility of the caecum, and that this explains why two-thirds of the cases occur in children less than one year old. Intussusception is met with in four chief situations: (a) the ileo-caecal, which is said to be the most frequent, constituting 44% of all cases (Treves) ; (b) the enteric variety, involving the small intestine; (c) the colic form; (d) the ileo-colic, the ileum being invaginated through the ileo-caecal valve. Intussusception may be acute or chronic, some times lasting intermittently for years. The acute form is the most common. In young children there is severe pain, at first paroxys mal but later continuous; vomiting is less early and less con tinuous than in strangulation by bands, and tenesmus, much straining and the passage of blood and mucus from the anus are common. Collapse soon supervenes. Early in the case the ab domen is but little distended, and in about half the cases a distinct tumour can be felt. Sometimes the invaginated gut pre sents at the anus. Chronic intussusception occurs more frequently in adults than in children; the symptoms may resemble chronic enteritis and be so indefinite that the nature of the illness re mains undiagnosed until an acute attack supervenes, or the patient succumbs to the diarrhoea, vomiting and haemorrhage.
(4) Congenital Malformations of the Intestines.—Persistence of Meckel's diverticulum, a structure which passes between the navel and the middle of the ileum and represents the nutrient canal of the foetus, may act as a band. Cases have been recorded in which the small intestine ended in a blind pouch. Imperforate anus is a fairly frequent occurrence in young infants, but atten tion is usually called to the condition. Partial strictures of the intestine, if the stricture be not too narrow, may pass unnoticed for years, and final complete obstruction may result from a blockage of the stricture by some foreign substance such as a plug of hard faecal matter or a fruit stone.
(5) Impacted Foreign Bodies.—These are gall-stones, faecal concretions (enteroliths) and foreign bodies swallowed by acci dent or otherwise, though knives, coins, pipes, flints, etc., swal lowed by jugglers, are known to have passed by rectum without injury. The caecum and duodenum are favourite situations for obstruction. Foreign bodies may remain weeks or months in situ before giving rise to serious symptoms. Their diagnosis has been much simplified since the introduction of the X-rays.
The general symptoms of chronic obstruction are more or less alike. The patient is attacked with gradually increasing constipa tion, which may alternate with diarrhoea which is generally set up by the irritation of the retained faeces. In obstruction due to malignant growths low in the rectum the character of the motions is changed, they become scybalous, pipe-like or flattened. The abdomen becomes distended, and at intervals severe symp toms may supervene, consisting of pain and vomiting with com plete constipation owing to some temporary complete obstruction. The attacks usually pass off, and relief may be obtained naturally or by the administration of a purgative, but they have a tendency to recur and in malignant disease to increase to complete ob struction. Finally a seizure may persist and take on all the characters of an acute attack, and death may supervene from exhaustion, perforation or peritonitis, unless immediately treated. When it arises from simple stricture no tumour is to be felt, but in malignant disease the tumour may frequently be palpated, un less during an acute attack, when the abdomen is much distended with gas.
(i) Faecal Impaction is not uncommon in adult females who have suffered from chronic constipation. The common seat of the blockage is in the colon, chiefly in the sigmoid flexure and in the rectum, but it may occur in the caecum. The accumulation may form a doughy tumour, which in parts may be nodular and in tensely hard. The causes are due to the state of the contents of the bowel itself, to congenital or acquired weakness and diminished expulsive power of the bowel, or to painful affections of the anus, fissures, piles and painful bladder affections. The acute symptoms are always preceded by a prolonged period of malaise ; the breath is offensive and the tongue foul, and the temperature may be raised from the absorption of toxins. Faecal impaction requires the regular and repeated administration of large enemata, given through a long tube, together with the administration of calomel and belladonna. Large impacted masses in the rectum may be broken up and removed by a scoop.
(2) Strictures of the Intestinal Walk—Simple strictures are in frequent, and are dealt with by the operation of lateral anasto mosis. They follow dysenteric or tuberculous ulceration or the passage of gall-stones. Stricture due to carcinoma of the intes tinal wall occurs usually in the old or middle-aged, and the symp toms come on insidiously. As soon as the condition is diagnosed an attempt should be made to remove the tumour if freely mov able, or if this is not possible to afford relief by short-circuiting the intestine or by colotomy.
(3) Chronic Intussusception has been frequently mistaken in the diagnosis for rectal polypus, cancer, tuberculous peritonitis, etc. (Treves). If diagnosed it may be reduced by inflation with air, but frequently too many adhesions are present for this to be possible, and laparotomy with excision of the mass should be undertaken ; the results are said to be very encouraging.
(4) Compression of the Bowel due to a tumour or bands ex ternal to the bowel may occasionally give rise to obstruction. An exploratory operation should be undertaken for the excision of the tumour, or the separation of adhesions and release of the bowel, or if the intestines are much matted together by peritonitis an intestinal anastomosis may give relief. Obstruction due to paralysis of the muscular coat of the intestine has been described (adynamic obstruction), but its existence is a subject of dispute.