Incomplete digestion of gluten and casein proteins results in intestinal absorption of polypeptides (small protein fragments) that can become biochemically active triggering a range of symptoms, in particular gastrointestinal, neurological, and neuro-developmental disorders. The excretion of the polypeptides casomorphin or gliadorphin in the urine indicate milk or gluten intolerance.
Most people who have food allergies to milk and/or wheat also have problems with peptides from these foods interacting with brain biochemistry causing opiate-like effects. 10 mL of first morning urine before food and drink is preferred.