Symptoms of indigestible diarrhea in 4-month-old babies can appear as abdominal pain and bloating, decreased appetite, diarrhea, sour stools and so on. 1. abdominal pain and distension: abdominal pain and distension is a relatively common symptom, manifested as abdominal cramping abdominal pain, abdominal pain can occur during defecation, accompanied by intestinal tinnitus symptoms. 2. loss of appetite: due to the presence of symptoms of indigestion, gastrointestinal peristalsis slows down, can also lead to loss of appetite, it is recommended that oral enhancement of gastrointestinal peristalsis and digestive function of drugs, such as probiotics to treat. 3. Diarrhea: It can also lead to diarrhea symptoms, manifested as egg-shaped stools or soft yellowish stools, there can be abdominal pain before defecation, after defecation abdominal pain symptoms disappear. 4. Sour and smelly stools: Sour and smelly stools can occur when there is indigestion, first of all, pay attention to adjust the diet structure, do not eat too much, eat small meals, eat easy to digest food. 4 months baby indigestion diarrhea, it is recommended to consult the pediatric department of the regular hospital for diagnosis and treatment.