This study is a prospective, single center, practical, and observational open clinical study.

Infant enterostomy is one of the emergency surgeries in pediatric gastroenterology. The most common underlying conditions during infancy include necrotizing enterocolitis, intestinal necrosis, intestinal perforation, and congenital gastrointestinal malformations. Necrotizing enterocolitis also serves as a major cause of short bowel syndrome in infants. Infants with small bowel stoma leading to short bowel syndrome face a higher incidence of complications compared to adults. Additionally, small intestinal stomy inevitably come with various complications such as infection, electrolyte imbalance, nutrient deficiencies, and malnutrition.

Currently, both domestic and international studies have shown that breast milk is the preferred choice for infant nutrition. The benefits of breastfeeding have been widely reported. For postoperative infants with digestive tract surgery, breast milk's immunoglobulins and prebiotics can help promote beneficial gut bacteria and bioactive proteins (such as lactoferrin, lysozyme, and lipoproteins), growth factors that facilitate intestinal adaptation and maturation processes while enhancing feeding tolerance and preventing infections or inflammatory disorders.

However, according to literature reports on clinical practice operations after digestive tract surgery even if early breastfeeding was initiated in 88% of cases; only 44% of infants were still being breastfed at discharge. This is due to feeding intolerance following breastfeeding which manifests as gastric retention, abdominal distension, diarrhea etc., not only delaying growth but also prolonging hospital stay while causing other adverse clinical outcomes. Some discharged infants who started breastfeeding experienced diarrhea and dehydration leading to readmission. Clinically speaking this issue has often been addressed by substituting feeds with enteral nutrition preparations (deep hydrolyzed formulas or free amino acid formulas).

The objective of this study is to assess the impact of enteral nutrition, which involves selecting appropriate preparations and human breast milk based on the child's intestinal tolerance, on growth and developmental outcomes in children following enterostomy. Additionally, we aim to investigate its effects on postoperative intestinal permeability, stoma output, gut microbiota and metabolites, sepsis incidence, colitis occurrence as well as bile stasis.

Inclusion Criteria:

• After birth, infants aged 0-6 months (including neonates) undergo small bowel ostomy for various reasons.

Exclusion Criteria:

• Primary liver and kidney dysfunction, congenital multiple malformations and chromosomal abnormalities.

Infants, undergo enterostomy for various reasons within the age range of 0-6 months