Four-month-old babies have been foam and mucus in the stool to consider the possibility of milk protein allergy, Clostridium difficile enteritis and other diseases, usually using dietary adjustments and drug therapy. 1. Milk protein allergy: can appear in the stool has been foam and mucus phenomenon, at this time, such as breastfeeding, mothers need to avoid milk, eggs, soy, peanuts, nuts, fish, shrimp, shellfish and seafood and other foods; such as artificial feeding needs to be replaced with moderately hydrolyzed milk powder or deeply hydrolyzed milk powder or amino acid milk powder, observation of the baby’s stools, such as stools with more water, can drink oral rehydration salts, clostridium difficile bacteria, such as drugs, to relieve the symptoms. Symptoms. 2. Clostridium difficile enteritis: with inappropriate abuse of antibiotics, causing intestinal flora disorders, micro-ecological imbalance related to the stool can also appear to have foam and mucus, at this time should be immediately discontinued all antibiotics, the use of metronidazole or vancomycin treatment; at the same time, can follow the doctor’s instructions to use oral rehydration salts, Saccharomyces boulardii, and other drugs. Four-month-old babies have been foamy stool and mucus may also be other reasons, it is recommended to consult a doctor in a timely manner, a clear diagnosis and follow the doctor’s instructions for treatment. All of the above drugs should be used under medical supervision, avoid self-medication.