Intussusception (Intestinal Obstruction)

Intussusception is a medical emergency and is a condition that is as a result of one part of the intestine sliding into another. This sliding is similar to how a telescope folds into itself and the intestinal prolapse results in obstruction. Thus, food and/ or fluid cannot move through the abnormal intestinal segment.

In addition to these, the blood supply to the prolapsed area is also affected. Intussusception can occur anywhere in the gastrointestinal (GI) tract, however, it most frequently occurs where the small and large intestines meet.

Epidemiology and Clinical Presentation

Infants in their 6th – 36th month of life, presenting with intestinal obstruction, more often than not have intussusception as the cause. Almost 6 in every 10 children affected will be younger than the age of one year and up to 90% of them are younger than 2 years.

The condition is less common before the age of 3 months and after the age of 6 years. Intussusception in younger and older children is often associated with conditions like lymphoid hyperplasia (an increase in the number of cells in lymph nodes).

Intestinal prolapse into itself occurs with a classic triad of vomiting, abdominal pain with an intermittent frequency and a palpable mass in the right upper abdominal quadrant. In addition to the triad, there may be gross or occult blood found when a rectal examination is done.

Together, these symptoms represent a very good positive predictive value. Other symptoms that may occur with intussusception include nausea, lethargy, and mucous inside of the stools.

Pathophysiology

The part of the bowel that prolapses is called the intussusceptum and the distal part of the affected segment that receives the intussusceptum is called the intussuscipiens. The exact cause of intussusception has not been clearly identified, but it is most frequently believed to be associated with lymphoid tissue hyperplasia.

This hypothesis possibly explains why intussusception is not seen in children younger than 3 months old, since these children still have naïve immune systems.

In older infants and adults, causes of intussusception include malignancies (e.g. colorectal cancer), benign neoplasms (e.g. intestinal polyps), congenital anomalies (e.g. cysts), inflammatory processes (e.g. appendicitis), and trauma (e.g. hematoma). Lead points (i.e. causes) identified in these groups of patients tend to be malignant in the large intestines and benign in the small intestines, in most cases.

Diagnosis and Treatment

On physical examination, a palpable mass found may be indicative of intussusception. Ultrasound may be used to identify the mass and is the first line tool used to examine patients suspected of having the condition. Once intestinal prolapse has been diagnosed, surgical intervention may be required to push the intestines back to their physiological positions. Intestinal blockage may first be treated with a contrast or air enema by a radiologist.

If the enema proves unsuccessful, surgery is done and parts of the intestines that may have died due to the prolapse are removed. Antibiotic therapy is indicated in cases of infection and intravenous fluids and feeding are given until the child has normal bowel movements.

Failure to treat intussusception is almost always fatal. Although early treatment has a great outcome, there is always a risk of recurrent prolapse.