Using a four-week randomized, crossover study design, we will assess the impact of 2 weeks of a high bile acid-binding blenderized diet, compared to 2 weeks of a low bile acid-binding blenderized diet, on gastric and salivary bile acid concentrations within individual participants. Four weeks of an amino acid formula will be a comparator group.

Pediatric patients ages 5 to 21 in the randomized arm Inclusion criteria

• receive at least 80% of their nutritional needs via gastrostomy
• receive blenderized feeds or will start receiving blenderized feeds
• have no known allergies to ingredients in blenderized feeds;
• receive their bolus feeds within 30 minutes or less
• can receive their feeds by syringe push Exclusion criteria
• have undergone anti-reflux surgery
• receive post-pyloric feeds
• are allergic to any component of the administered diets
• cannot receive their gastrostomy feeds over 30 minutes
• require a feeding pump for feed administration (as the H-BBB is too thick for pump administration).

Pediatric patients ages 5 to 21 in the observational arm Inclusion

• receive at least 80% of their nutritional needs via gastrostomy
• are taking an amino acid formula
• have not undergone antireflux surgery Exclusion
• have undergone anti-reflux surgery
• receive post-pyloric feeds
• are not receiving an amino acid-based formula.