Some infants may experience yellow or green, loose stools shortly after birth, with frequent bowel movements, but they remain in good spirits, without vomiting, and have a good appetite. As they grow older, diarrhea often disappears naturally after introducing complementary foods. Infants with physiological diarrhea may develop skin rashes, fever, and other symptoms after consuming foreign proteins such as milk or eggs, or even after exposure to sunlight, wind, or friction from clothing.