Necrotising enterocolitis (NEC) in modern paedi-atric practice refers to the idiopathic, often severe enterocolitis that occurs in premature infants in neonatal intensive care units. The only definite risk factor for NEC is prematurity and the majority of cases occur in infants who weigh less than 2000 g, with both the incidence and mortality increasing with decreasing birth weight and gestational age (Holman et al. 1997). NEC may also occur in full-term infants with a predisposition, such as those who have had surgery for congenital heart disease or who have had abdominal surgery. An acute enteritis may be seen in Hirschsprung's disease. Vascular lines and generalized sepsis have been loosely associated with NEC.
Inflammation begins in the mucosa of the bowel wall and then extends through the whole bowel wall. The terminal ileum and the proximal colon are the most commonly affected areas.
Details of the acute radiological findings are described elsewhere in the text as they are not specific to the colon. However, the complications of NEC often do involve the colon with approximately 10%-20% of survivors developing strictures of the
bowel which may be single or multiple. Despite NEC most commonly affecting the distal ileum and the ascending colon the majority of strictures affect the descending colon (Fig. 6.15). Infants who have developed strictures may be asymptomatic but most present clinically within weeks to months of the initial diagnosis of NEC, usually with a distended abdomen, intolerance of feeds or with obstruction. In those infants who have had surgery to raise an ileostomy or colostomy it is essential to assess the distal bowel using a loopogram or contrast enema before reversal of the stoma.
Was this article helpful?