A 1.5-month-old baby crying intensely before passing stool is often related to immature digestion, gas, or infant colic, which is quite common at this age as the gut is still developing. However, in such a young infant, every medicine needs a very careful review because symptoms can overlap with feeding intolerance or infection. Colistin sulphate is an antibiotic and is usually used only when there is a confirmed bacterial infection, not just for colic or stool-related discomfort. Probiotics like Bifilac and drops such as Neosmile are sometimes given to improve gut balance or reduce gas, and they are generally supportive, but their role depends on the exact diagnosis. Breastfeeding should not be stopped unless a paediatrician specifically advises it, as it remains the best and safest nutrition at this age and also helps reduce infections and improve digestion. Formula or milk supplements like Nusobee may be recommended only in specific situations. If the baby continues to cry excessively, has blood in stool, poor feeding, fever, or poor weight gain, a re-evaluation by a paediatrician is important to confirm whether the current treatment is appropriate.