Intussusception

An intussusception (a blockage of the intestine) is a medical condition in which a part of the small intestine has invaginated into another section of intestine, similar to the way in which the parts of a collapsible telescope slide into one another. The part which prolapses into the other is called the intussusceptum, and the part which receives it is called the intussuscipiens.

Symptoms

Early symptoms can include nausea, vomiting - sometimes bile stained (green colour), pulling legs to the chest area, and intermittent moderate to severe cramping abdominal pain. Later signs include rectal bleeding, often with red currant jelly stool (stool mixed with blood and mucus), and lethargy. Physical examination may reveal a sausage-shaped mass felt upon palpation of the abdomen.

In children or those too young to communicate their symptoms verbally, they may cry, draw their knees up to their chest or experience dyspnea with paroxsyms of pain.

Fever is not a symptom of intussusception. However, intussusception can cause a loop of bowel to become necrotic. This leads to perforation and sepsis, which causes fever.

Diagnosis

Intussusception is often suspected based on history and physical exam, including observation of Dance's sign. Per rectal examination is particularly helpful in children as part of the intussusceptum may be felt by the finger. A definite diagnosis often requires confirmation by diagnostic imaging modalities. Ultrasound is today considered the imaging modality of choice for diagnosis and exclusion of intussusception due to its high accuracy and lack of radiation. A target-like mass, usually around 3 cm in diameter, confirms the diagnosis. An x-ray of the abdomen may be indicated for evaluation of intestinal obstruction or the presence of free intraperitoneal gas; the latter finding would imply that bowel perforation has already occurred. In some institutions, air enema is used for diagnosis as the same procedure can be used for treatment.

Treatment

In the developed world the condition is not immediately life-threatening. The intussusception is usually treated with either a barium or water-soluble contrast enema or an air-contrast enema, which both confirms the diagnosis of intussusception, and in most cases successfully reduces it. The success rate is over 80%. However, approximately 5-10% of these recur within 24 hours.

If it cannot be reduced by an enema or if the intestine is damaged, then a surgical reduction is necessary. In a surgical reduction, the abdomen is opened and the part that has telescoped in is squeezed out (rather than pulled out) manually by the surgeon or if the surgeon is unable to successfully reduce it or the bowel is damaged, the affected section will be resected. More often, the intussusception can be reduced by laparoscopy, whereby the segments of intestine are pulled apart by forceps.

Prognosis

Intussusception may become a medical emergency if not treated early, as it will eventually cause death if not reduced. In developing countries where medical hospitals are not easily accessible, especially when the occurrence of intussusception is complicated with other problems, death becomes almost inevitable. When intussusception or any other severe medical problem is suspected, the person must be taken to a hospital immediately.

The outlook for intussusception is excellent when treated quickly, but when untreated it can lead to death within 2–5 days. Fast treatment is a necessity, because the longer the intestine segment is prolapsed the longer it goes without bloodflow, and the less effective a non-surgical reduction will be. Prolonged intussusception also increases the likelihood of bowel ischemia and necrosis, requiring surgical resection.