Inclusion Criteria:
Inclusion Criteria for Stage 1:
- Singleton full term birth with birth weight of > 2500g.
- Infant between 0 and 60 days of age.
- Discontinuation of medications that might affect gastrointestinal (GI) tolerance.
- Infant is exclusively formula-fed a full-lactose, intact cow milk protein-based infant formula (CMF) for less than 7 days prior to enrollment.
Inclusion Criteria for Stage 2:
- Infant was fed according to protocol in Stage 1 of the study.
- Infant was identified as being fussy using the Intolerance Assessment Tool in Stage 1.
Exclusion Criteria:
Exclusion Criteria for Stage 1:
- Chromosomal or major congenital anomalies.
- Suspected or known metabolic or physical diseases affecting infant feeding and/or metabolism.
- Hospitalization, other than for delivery, prior to enrollment.
- Severe uncontrolled eczema, visible bloody stools or milk protein allergy prior to enrollment.
- More than 1 substitution of an infant formula other than full-lactose, intact cow milk formula (CMF) since birth.
- Use of a prokinetic drug within 7 days before enrollment.
Exclusion Criteria for Stage 2:
- Infant's intolerance symptom was caused by another reason, for example known infection/illness, food allergy, or response to vaccination(s).
- Infant has immunization(s) within 3 days of enrollment in Stage 2.