Final answer:
The symptoms and diet described suggest that the baby could be suffering from iron deficiency anemia, due to the introduction of whole milk which is a poor source of iron and may decrease iron absorption.
Step-by-step explanation:
The symptoms described in the question, such as fatigue, irritability, poor appetite and being fed whole milk, could be indicative of iron deficiency anemia. Babies fed with whole milk receive minimal iron as milk is a poor source of this nutrient, and whole milk can also lead to internal bleeding in some infants, which can contribute to iron deficiency. Additionally, cow's milk is low in iron, and it can also decrease the absorption of iron and can replace foods in the diet that are better sources of iron. Given the symptoms and dietary context, iron deficiency anemia is a plausible diagnosis. It is important for a healthcare professional to evaluate the baby to confirm the diagnosis and to recommend appropriate treatment or dietary adjustments.