The baby has had diarrhea for more than a month, and changing the formula hasn't helped. What should I do?

If a baby has had diarrhea for more than a month and changing formulas has proven ineffective, the cause might be infectious factors, such as viral, bacterial, or parasitic infections affecting the intestines. These infections can disrupt the balance of normal intestinal flora and damage the mucosal structure, leading to diarrhea. A common example is rotavirus infection.

Non-infectious factors could also be responsible, such as an immature digestive system in the baby, which results in weak digestion and absorption of food. Cow's milk protein allergy may also be a cause; even switching formulas may not relieve symptoms if an appropriate specialized formula has not been selected. Another possibility is lactose intolerance, where a deficiency of lactase in the intestine prevents complete digestion of lactose in the formula, resulting in diarrhea. It is recommended to take the baby to see a doctor for detailed examinations, such as stool routine tests, blood routine tests, allergen testing, and lactose intolerance testing. If the diarrhea is infectious, treatment should target the specific pathogen—for example, bacterial infections may require antibiotic use. For babies with cow's milk protein allergy, hypoallergenic formulas such as extensively hydrolyzed or amino acid-based formulas should be selected under a doctor's guidance.

If lactose intolerance is present, lactose-free formula or lactase supplements may be used. Additionally, keeping the baby's abdomen warm and appropriately supplementing with probiotics to regulate intestinal flora, such as Bifidobacterium quadruple live tablets, may be beneficial.

Mothers who are breastfeeding should maintain a light diet and avoid spicy, greasy, or irritating foods.