Table 1.

Systematic review inclusion and exclusion criteria for GE studies using formula/enteral feeds or breast milk

Inclusion criteria	Exclusion criteria
Patient cohort	Patient cohort
All studies on preterm infants	Adult studies (>16 years)
All studies on children (birth – 16 years)	Animal studies
Intervention	Intervention
Whole protein formula or feeds	Paediatric formula/feeds assessing impact of osmolality, carbohydrates and fat content on GE
Partial or extensively hydrolysed casein formula or feeds
Partial or extensively hydrolysed casein formula or feeds	Paediatric formula/feeds that are mixed at a non-standard concentration
Mix of casein and whey protein, hydrolysed or whole formula or feeds	Paediatric formula/feeds that are pre-thickened
	Adult feeds
Amino acids formula or feeds	Any feeds tested in animal models
Comparison	Comparison
Whole protein formulas versus breast milk	Adult feeds
Whole protein versus hydrolysed (casein/whey) formula/feeds	Animal models
Hydrolysed (casein/whey) versus amino acid formula/feeds
Amino acid versus whole protein formula/feeds
Outcome measurements	Outcome measurements
Scintigraphy (Tc99 sulfur colloid scan)	Paracetamol absorption
13C-OABT	13C-acetate BT
13C-Na- OABT	Ultrasound
	Manometry