Symptoms Based Awareness Confirmation Study - CoMiSS Validation

Inclusion Criteria: * Male or female infant aged up to 6 months old * Has been fed exclusively on cow's milk infant formula for at least one week * Has CMPA symptoms that have been present for at least one week, and that developed within the first two months of starting cow's milk infant formula * In the opinion of the investigator, requires a two week elimination diet with Amino Acid Formula (AAF). * Had a gestational age at birth of 37 to 42 weeks * Had a birthweight of 2500 g to 4500 g * Informed consent signed by both parents, liable parent or legal guardian (if applicable). Exclusion Criteria: * Has ever received either an extensively hydrolysed infant formula or an AAF prior to enrolment * Has a fever above 38.5°C at enrolment * Has ever experienced a medically diagnosed serious anaphylactic reaction * Use of antibiotic drugs at enrolment. Infants may be enrolled if antibiotics have been stopped at least 7 days prior to enrolment. (Antibiotic treatment can be initiated during the study if an infant develops a condition after enrolment that requires antibiotic treatment). * Infant with a health condition or family situation that makes the infant unsuitable to participate in the trial according to the opinion of the investigator * Infant or infant's carers are unable to comply with trial procedures * Currently participating or has participated in another clinical trial within 4 weeks prior to trial start.