Comparing the Gastric Transit of Commercial Milk and A2 Milk

Inclusion Criteria: * Ability/desire to provide informed consent * Aged 18 to 65 years of age inclusive at screening * Milk intolerant and identified as a lactose maldigester while participating in the Milk Protein Study (applicable only for subjects from the previous milk protein study and not applicable for new subjects) * Current or recent history of intolerance to or avoidance of dairy of at least one month duration (by self-report and self-reported symptoms). * Willing to return for all study visits and complete all study related procedures * Able to understand and provide written informed consent in English Exclusion Criteria: * • Currently pregnant * Diagnosed with any of the following disorders known to be associated with abnormal gastrointestinal motility such as; Gastroparesis, amyloidosis, neuromuscular diseases (including Parkinson's disease), collagen vascular diseases, alcoholism, uremia, malnutrition, or untreated hypothyroidism * History of surgery that alters the normal function of the gastrointestinal tract including, but not limited to: gastrointestinal bypass surgery, bariatric surgery, gastric banding, vagotomy, fundoplication, pyloroplasty \[Note: history of uncomplicated abdominal surgeries such as removal of an appendix more than 12 months prior to screening will not be excluded\] * Past or present : Organ transplant, chronic pancreatitis, pancreatic insufficiency, symptomatic biliary disease, Celiac disease, chronic constipation, diverticulo…