Intestinal obstruction is the partial or complete mechanical or nonmechanical blockage of the small or large intestine.
There are two types of intestinal obstructions—mechanical and nonmechanical. Mechanical obstructions occur because the bowel is physically blocked and its contents cannot get past the obstruction. Mechanical obstructions can occur for several reasons. Sometimes the bowel twists on itself (volvulus) or telescopes into itself (intussusception). Mechanical obstruction can also result from hernias, impacted feces, abnormal tissue growth, the presence of foreign bodies in the intestines, or inflammatory bowel disease (Crohn's disease). Nonmechanical obstruction, called ileus, occurs because the wavelike muscular contractions of the intestine (peristalsis) that ordinarily move food through the digestive tract stop.
Mechanical obstruction in infants
Infants under one year of age are most likely to have intestinal obstruction caused by meconium ileus, volvulus, and intussusception. Meconium ileus, which is the inability to pass the first fecal excretion after birth (meconium), is a disorder of newborns. It is an early clue that the infant has cystic fibrosis. In meconium ileus, the material that is blocking the intestine is thick and stringy, rather than the collection of mucus and bile that is passed by normal infants. The abnormal meconium must be removed with an enema or through surgery.
Volvulus is the twisting of either the small or large bowel. The twisting may cut off the blood supply to the bowel, leading to tissue death (gangrene). This development is called a strangulating obstruction.
In intussusception, the bowel telescopes into itself like a radio antenna folding up. Intussusception is most common in children between the ages of three and nine months, although it also occurs in older children. Almost twice as many boys suffer intussusception as girls. It is, however, difficult for doctors to predict which infants will suffer from intestinal obstruction.
Tish Davidson, The Gale Group Inc., Gale, Detroit,