Certain combinations of fruits should be avoided due to potential digestive issues and health concerns:

1. Orange and Carrot: Mixing oranges and carrots can lead to excess bile reflux, potentially causing heartburn.
2. Papaya and Lemon: Consuming papaya and lemon together may lead to anemia and hemoglobin imbalance, which is particularly risky for children.
3. Orange and Milk: Combining orange with milk can be challenging for digestion due to the interaction between orange acid and milk enzymes, leading to potential health issues.
4. Guava and Banana: Eating guava and banana together may increase the risk of acidosis, nausea, gas, headaches, and other discomforts.
5. Pineapple and Milk: The bromelain in pineapple can cause digestive problems when mixed with milk, resulting in stomach issues like gas, nausea, and stomach pain.
6. Banana and Pudding: The combination of banana and pudding is difficult to digest and may stimulate toxin production, especially concerning for children.