INTESTINAL OBSTRUCTION (Ilius), in surgery, a condition in which the onward passage of the faeces is prevented. It is often associated with phenomena due to strangulation of the gut, leading to gangrene, and with systemic poisoning due to the absorption of toxins, resulting from the decomposition of the retained faeces. Intestinal obstruction may be conveniently divided into acute and chronic.
Acute Intestinal Obstruction forms one of the most urgent of surgical emergencies. The following are its chief causes: (i) strangulation by bands or adhesions or through apertures; (2) volvulus; (3) the impaction of foreign bodies; (4) acute intussusception; (5) strangulation over a band or acute kinking of the gut; (6) the termination supervening on chronic obstruction; (7) congenital malformations of the intestines.
Strangulation by Bands or Adhesions or through Apertures. These terms are applied to obstruction by constricting bands within the abdomen. These may be the result of the stretching of old inflammatory adhesions, the result of former peritonitis. These bands are commonly situated between different parts of the mesentery or between the mesentery and another organ such as the appendix. Two methods of producing strangulation exist; in the first the bowel passes under an arch or loop formed by some short constricting band and cannot return, or if the band is long it may form a noose in which the bowel is strangled (fig. l); in the second the remains of a foetal structure (Meckel's diverticulum) becoming adherent to some FIG. I. Diagram to other organ may ensnare the intestine in s how how Strangulathe loop. A coil of intestine may also slip tion by a Band may into a hole in the mesentery or omentum take place, or find its way into a pouch of peritoneum, forming what is known as an internal hernia. The onset of symptoms is sudden and abrupt. The patient is seized with acute abdominal pain associated with collapse. The pain is usually referred to the region of the umbilicus; this localization, however, is no guide to the situation of the lesion. Vomiting is early and persistent, generally assuming a faecal character between the second and the ninth day. 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. This form of obstruction is most frequent in young people, and there is usually a history of previous peritonitis. 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.
Volvulus means a torsion or twisting of the gut. 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 situation in which volvulus most commonly takes place, but it may occur in the caecum and small intestine. When once present, plastic peritonitis fixes the coil in position and the blood supply becomes obstructed. Volvulus is generally preceded by a history of chronic constipation. The acute symptoms start abruptly and are similar to those of internal strangulation, but the pain at first is more intermittent in type. There is usually early tender- how Volvulus" may take ness over the spot and constipation is place, 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 surgical interference death is inevitable.
Impacted Foreign Bodies. Gall-stones may cause obstruction when they are of large size. These gall-stones when lodged in the intestine may there be enlarged by subsequent accretion. Leichenstern describes such a stone with a circumference of 5 in., and Sir F. Treves removed from the intestine of an old lady a calculus, the large size of which was due to layers of magnesia, the patient having takeru FIG. 2. Diagram to show carbonate of magnesia daily for many years. Gall-stones may give rise to intermittent sub-acute attacks of incomplete obstruction and finally give rise to an acute attack accompanied by severe pain and vomiting, which is constant and early becomes faecal. The abdomen is soft and flaccid and the affected coil is rarely to be felt. The symptoms vary with the situation of the obstruction and are generally more urgent the nearer to the duodenum. Foreign bodies that have been swallowed by accident or otherwise may give rise to obstruction, though extraordinary objects, as knives, coins, pipes, flints, etc. swallowed by jugglers, are known to have passed by rectum without injury. In cases where the foreign body lodges in the intestine the caecum and duodenum are favourite situations for obstruction. In the museum of the Royal College of Surgeons is a specimen in which the duodenum is blocked by a mass of pins weighing nearly a pound. Foreign bodies may remain weeks or months in situ before giving rise to serious symptoms, the progress of the larger substances being, marked by temporary obstruction. In a case quoted by Duchaussoy the obstructing mass consisted of over 700 cherry stones. The diagnosis of obstruction by foreign bodies has been much simplified since the introduction of the X-rays. Enteroliths may themselves cause obstruction. They may consist of masses of indigestible vegetable material matted together with faeces and mucous. In Scotland they are frequently found to consist of husks of coarse oatmeal (aenoliths). In thin persons large enteroliths and foreign bodies may be palpable. The symptoms are those similar to obstruction by a large gall-stone.
Acute Intussusception forms about 30% 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 referring to the diagram (fig. 3). The invaginated portion is termed the intussusceptum, and the lower portion which it enters is known as the intussuscipiens. It is to the constriction of the vessels in the entering mesentery and later to their possible complete 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 adhesions between the serous coats of the entering _ and returning parts leads to irreducibility lagram of the j ntussusce ption. A cure occasionally l*~ ensues from spontaneous reduction of the i tates pagination, or again permanent stenosis of P' ace - the intestine may result from the adhesion of the opposed surfaces, or the occurrence of gangrene may lead to perforation of the intestine with acute septic peritonitis. Occasionally when there is no perforation adherence takes place between 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 prpduced._ Polypoid tumours or masses of worms, or masses of irritating ingesta, are said to lead to its occurrence. X. Dolore and R. Leriche contend that the primary factor is congenital mobility of the_ caecum. They state that in 48 % of foeti the caecum is mobile in half, fixation gradually going on; while in 8-5% of adults it retains its mobility. They thus endeavour to account for the fact that in 300 collected cases 204 occurred 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) ; (6) the enteric variety, involving the small intestine; (c) the colic form; (d) the ileo-colic, the ileum being invaginated through the ileocaecal valve. Intussusception may be acute or chronic, sometimes lasting intermittently for years. The acute form is the most common. In young children an attack occurs with severe pain, at first paroxysmal but later continuous; vomiting is less early and less continuous than in strangulation by bands, and diarrhoea tenesmus, much straining and the passage of blood mucus from the anus are common. Collapse soon supervenes. Early in the case the abdomen is but little distended, and in about half the cases a distinct tumour can be felt. In some cases the invaginated gut may be felt protruding through the sphincter. Chronic intussusception occurs more frequently in adults than in children; the symptoms may resemble chronic enteritis and be so masked that the nature of the illness remains undiagnosed until an acute attack supervenes, or the patient succumbs to the diarrhoea, vomiting and haemorrhage.
Congenital Malformations of the Intestines. 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 attention 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.
Treatment of Acute Intestinal Obstruction. Early diagnosis and early laparotomy are essential, and it is important to operate before the patient is poisoned by the absorption of toxins from the bowel. To administer purgatives is worse than useless. Of massage and abdominal taxis Sir F. Treves says: " These are to be condemned, as they may rupture the already moribund bowel and make effective a threatened perforation. These measures are for the most part feeble excuses for avoiding or delaying the operation." The operation may be undertaken in one or two stages, and includes the opening and evacuation of the distended intestines and the search for and reduction or removal of the obstruction.
Chronic Intestinal Obstruction. The causes of chronic obstruction are very numerous, and may be divided into the following groups: (i) intra-intestinal conditions, i.e. the impaction of foreign bodies and impaction of faeces; (2) affections of the intestinal wall such as stricture, new growths in the intestine, particularly those of a malignant type, adhesions or matting together of the intestines from peritonitis or kinking of the gut from disease of the mesenteric glands; (3) chronic intussusception; (4) compression of the bowel by a tumour or bands developing outside the intestine. Of these the commonest are malignant growths and faecal impaction.
The general symptoms of chronic obstruction are more or less alike. The patient is attacked with gradually increasing constipation, which may alternate with diarrhoea which is generally set up by the irritation of the retained faeces. In obstruction due to malignant growths the character of themotions is changed, they become scybalous, pipe-like or flattened. The abdomen becomes distended, and at intervals severe symptoms may supervene, consisting of pain and vomiting with complete 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 obstruction. 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 be frequently palpated, unless during an acute attack when the abdomen is much distended with gas.
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 intensely 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.
Strictures of the Intestinal Wall. Simple strictures are infrequent, and are dealt with by the operation of lateral anastomosis. They follow dysenteric or tuberculous ulceration or the passage of gallstones. Stricture due to carcinoma of the intestinal wall occurs usually in the old or middle-aged, and the symptoms come on insidiously. As soon as the condition is diagnosed an attempt should be made to remove the tumour if freely movable, or if this is not possible to afford relief by short-circuiting the intestine or by colotomy.
Chronic Intussusception has oeen 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.
Compression of the bowel due to a tumour or bands external 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. (H. L. H.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)