Why does a child's stool smell sour

Patient's question:

Detailed medical condition and consultation purpose: Stool has a relatively strong sour odor
Current general condition: Appetite and urination are normal, bowel movement every 3-4 days
Auxiliary examinations:
Other: Drink pediatric star tea for the first time
Supplementary information: The child is breastfed

Doctor's answer:

Hello! The baby's stool has a sour odor, which may indicate indigestion. It could be due to excessive consumption of protein-rich foods. These proteins can neutralize stomach acid, reducing the acidity of gastric juice and hindering the complete digestion and absorption of proteins. Additionally, bacterial decomposition in the intestinal tract can contribute to the strong odor of the stool.
It is recommended to dilute the formula milk slightly. Breastfeeding mothers should eat more vegetables and fruits, drink plenty of water, and consume appropriate amounts of meat, eggs, and fish while reducing the intake of high-fat foods. This will ensure that the breast milk is nutritionally balanced and easily digestible. Additionally, you can take Mamikai (a probiotic supplement).