Abstract
A female infant was born 812 g in weight at 30 weeks of gestation. Breast milk feeding with Lactobacillus bifidus was initiated at 1 day of age. At 36 days of age, necrotizing enterocolitis developed and laparotomy was performed for intestinal perforations at 44 days of age. Multiple intestinal perforations were observed. The necrotic intestine was resected, and end-to-end anastomosis was performed, which resulted in about 50 cm in length of the residual small intestine. Breast milk was restarted 11 days after the operation, and the amount of breast milk was increased without problems. The general condition of the infant improved. At 90 days of age, however, diarrhea developed, and the milk was changed to MA-1 owing to suspected lactose intolerance. At 123 days of age, bloody stool, abdominal distension, and an increase in CRP level were observed. Milk allergy was suspected, and MA-1 was changed to an elemental formula, but no improvement was observed. After fasting and bowel rest, enteral nutrition was initiated, but the marked intestinal distension did not improve. Since gastrointestinal series confirmed the absence of intestinal obstruction, abnormal gas retention in the small intestine due to small intestinal bacterial overgrowth (SIBO) was considered, and metronidazole administration was initiated. After a few days, the amount of intestinal gas markedly decreased, and symptoms did not recur after the resumption of the elemental formula. In this patient, SIBO may have been caused by various factors such as poor intestinal peristalsis due to immaturity, necrotizing enterocolitis, or gastrointestinal allergy.
