It is thought that the intestinal tissues are somehow weakened by too little oxygen or blood flow. When feedings are started and the food moves into the weakened area of the intestinal tract, bacteria from the food can damage the intestinal tissues. The tissues may be severely damaged and die, which can cause a hole to develop in the intestine. This can lead to severe infection in the abdomen.
Premature babies have body systems that are more immature.
NEC is rare in babies who have not received feedings. When there is too little oxygen, the body sends the most blood and oxygen to essential organs and away from the intestinal tract. This can result in lowered oxygen in the gastrointestinal circulation. This thickens the blood and makes oxygen transport more difficult. This allows the bacteria normally present in the intestinal tract to leak out into the abdomen and cause infection.