Radiology

Small bowel obstructions are usually caused by scar tissue, hernia, or cancer. In the United States, most obstructions occur as a result of prior surgeries. The bowel often forms bands of scar (called adhesions) after being handled during an operation. The more surgeries that involve the bowel, the more scars are likely to form. If the bowel becomes trapped in adhesions, it may lead to a small bowel obstruction. In severe cases, the blood supply might be compromised, and the bowel tissues might die. This is a life-threatening situation.

• bilious vomiting
• abdominal distention
• obstipation

This is accomplished by inserting a nasogastric (NG) tube and operative intervention may be necessary.

Bowel oedema

This is also called bowel disease or gut oedema. It is caused by certain serotypes of E. coli bacteria that produce a powerful toxin (verotoxin). These toxins damage the walls of small blood vessels including those in the brain and cause fluid or oedema to accumulate in the tissues of the stomach and the large bowel. Damage to the blood vessels in the brain results in some of the characteristic signs. The specific E. coli are described as O138, O139 and O141. Disease is generally seen 1 to 4 weeks after weaning, the peak being at 10 days. It was very common when pigs were weaned at 5 to 8 weeks of age. Since weaning ages have reduced to 17 to 26 days and starter diets have been improved the disease in its classical form is rarely seen. The E. coli bacteria attach themselves to the finger-like villi in the anterior small intestine and produce the toxins. This mechanism is similar to that which occurs in post-weaning diarrhoea associated with different strains of E. coli. During sucking the secretory IgA immunoglobulin component in milk prevents the bacteria adhering. After weaning when the IgA has disappeared the pigs becomes susceptible to disease.

Sigmoid volvulus is a cause of large bowel obstruction and occurs when the sigmoid colon twists on its mesentery, the sigmoid mesocolon.

Rectal tube insertion is successful in treating 90% of cases 5. Occasionally patients suffer from recurrent sigmoid volvulus, for which a surgeon may consider sigmoid colopexy (surgical fixation of the sigmoid colon), or in the surgically unfit, a percutaneous endoscopic colostomy (PEC) might be performed.

The mortality rate is 20-25% 7. The most serious complication is bowel ischemia.