Answer: factitious disorder imposed on another
Explanation: Factitious disorder imposed on another is the most appropriate diagnosis on this scenario. Factitious disorder refers to a state of mental illness whereby an individual consciously creates a physical or mental distress in themselves. Factitious disorder may involve putting one's life or health status at risk intentionally.
However, in the scenario above, the factitious disorder was imposed on the baby or child by the mother by deliberately feeding the child with spoilt milk and rotten eggs in other to induce diarrhea.