The stool analysis on a nine-month-old infant showed occult blood.

Occult blood in the stool of a nine-month-old infant can be a sign of gastrointestinal irritation or bleeding. One common cause of occult blood in infants is an intolerance to cow’s milk protein. Therefore, it is crucial to ask if cow's milk has been introduced to the infant’s diet. This helps identify a potential cause of the symptoms and guides further management. While diet and other factors are also important, cow's milk introduction is a primary consideration for occult blood in this age group.