How to deal with curd-like stools in a five-month-old baby

Patient's question:

Age: Five and a half months
Since birth, she has been like this without knowing the reason. About her previous treatment and effectiveness: She eats lactase, doesn't smile much, has red dots on her neck, and has curdled milk in her stool. Is it okay to eat Smecta? Can she eat Mammae? What kind of assistance do you need: How to treat her seriously...

Doctor's answer:

The feces contain 80% water, with the remaining portion consisting of mucus, bacteria, and food residue. The frequency, color, and odor of stool vary among different age groups due to differences in dietary composition. In newborns, the first three days after birth, the stool is meconium, which is viscous, dark green or black, and odorless. After changing diapers, it transitions to yellow, becoming the typical stool of infants.
Medical Advice: For infants breastfed with human milk and before the introduction of solid foods, the stool is yellow or golden yellow, with a paste-like consistency. It may sometimes be slightly loose or greenish and have a slightly sour odor. The frequency of bowel movements is typically 2-4 times per day. If an infant who previously had one bowel movement per day suddenly increases to 4-5 times with continuously increasing fluid content, this should be considered a pathological condition. However, if the infant normally has 4-5 bowel movements per day, is in good health, and gaining weight, this is a normal phenomenon. After introducing solid foods, the frequency of bowel movements may increase, generally to 1-2 times per day.
For artificially fed infants, the stool is light yellow or gray, with a harder consistency due to the higher protein content in cow's milk, which has a distinct odor of protein fermentation. The frequency is typically 1-2 times per day, sometimes containing curds. For mixed-fed infants who also consume starchy foods, the stool frequency may not increase significantly, but the volume is larger, with a darker brown color and slightly softer consistency compared to purely cow's milk feeding. The odor may also become stronger. If the stool is green after adding vegetable puree, it indicates protein digestion issues. If the stool contains bubbles, it suggests poor carbohydrate digestion. If the stool appears oily, it indicates poor fat digestion. If the stool contains curds, it is usually due to undigested fat combined with calcium or magnesium to form soap-like lumps, which are not significant in quantity.