Green poop in a 5-month-old baby can be caused by improper feeding, digestive disorders or enteritis, which can be treated by improving feeding methods, keeping the baby warm or using medication. 1. Improper feeding: 5-month-old babies with green poop may be caused by improper feeding, such as feeding the child too little milk, or adding supplemental food too early or too much, which may lead to the child’s green poop. It is important to note that when adding complementary foods to your child, don’t add too much at once and feed your baby the right amount of milk. 2. digestive disorders: 5 months baby green poop may be recent cold and other digestive disorders, you can give the baby good warm measures to prevent the cold again, and can be used such as bifidobacteria, bacillus subtilis bacillus and other medications to regulate the treatment. 3. enteritis: 5 months baby green poop may be the recent misuse of food and other causes of enteritis caused by the baby through the appropriate amount of water, and laboratory tests clearly for the pathogen use of drugs, if the bacterial infection, can be given such as cephalexin and other anti-infective treatment. If it is a viral infection, there is no special treatment. When diarrhea is severe, oral montelukast can be used to stop diarrhea. Parents are advised to take their 5-month-old babies to the doctor for relevant examinations and standardized treatment once they find that their babies have green poop. The above medications should be used under the guidance of a doctor.