If you suspect a reaction, closely monitor the child's symptoms and keep a detailed log of everything they have ingested in the last 48 hours, as reactions can sometimes be delayed. While common symptoms like rashes or digestive issues (mucus/blood in stool) are often linked to diet, keep in mind that other factors like vaccinations or underlying issues like fissures can sometimes cause similar symptoms. Always consult your pediatrician before making major dietary changes, and if you are breastfeeding, your doctor may suggest an elimination diet for you to help your baby's gut heal.