The spectrum of ischemic bowel disease in the newborn.

In this review the author's opinion regarding the etiology of most cases of perinatal and neonatal bowel ischemia has been stated. It is recognized that the changes brough about by hypoxia (splanchnic shutdown, bowel ischemia) represent the "soil" on which other "seeds" can prosper. In its simplest form following acute ischemia, the processes of repair take over, leading to functional recovery and a presumably normal bowel. In those patients with more extensive initial damage, degrees of stenosis and even atresia may be expected as a result of the healing of the bowel. Rapidly evolving ischemia may produce perforations; these may be restricted and involve only very small areas of bowel or may be part of a more generalized involvement, possibly even with multiple perforations. In other infants, alterations of bacterial flora could contribute to the clinical picture of "necrotizing enterocolitis," and gas may or may not be present in the bowel wall. If the process of ischemia has been relatively mild, or bacterial overgrowth not particularly marked, some of the more obscure functional syndromes may be noted. The persistence of these obscure syndromes may in turn be related to incomplete phases of regeneration of the bowel that fall short of producing stenosis but lead to a mucosa that is not optimally functional.