Green stools in infants eating formula may be caused by too much iron in the formula, indigestion of infants, infants catching cold in the abdomen or infants adding some green complementary food. The causes of green stools in infants can be divided into two categories, physiological and pathological. Firstly, physiological reasons, if the infant eating milk powder green stools without crying, diarrhea and other symptoms, can be suspected that the milk powder in the iron more, not absorbed, resulting in feces green. If the infant also ate milk powder during the addition of other green vegetables supplemental food, may also be because the beginning of the addition of supplemental food, supplemental food can not be digested, resulting in green stools. Secondly, the pathologic cause is likely to be indigestion caused by a cold abdomen. The intestinal tract of infants and young children is relatively fragile, so if the abdomen is cold, it will easily cause indigestion, resulting in green stools. Prompt medical treatment is needed.