A stool frequency of 6–7 times/day in an exclusively breastfed 4.5-month-old can sometimes still be within normal variation if the baby is active, feeding well, gaining weight, and has no blood, fever, vomiting, or dehydration.
Acidic stool and reducing substances may suggest temporary carbohydrate/lactose malabsorption, commonly seen after a viral gut infection, and it often improves gradually on its own.
Exclusive breastfeeding should usually be continued if the baby is otherwise thriving. Formula is not always immediately required unless there is poor weight gain, persistent worsening diarrhea, dehydration, significant diaper rash, blood in stool, or concern for cow milk protein allergy/other intestinal conditions.
Next Steps
You may discuss with your pediatrician regarding monitoring weight gain, hydration, and whether a short trial of lactase drops/probiotics is appropriate depending on the clinical picture.
Health Tips
Please seek review urgently if there is lethargy, reduced urine output, persistent vomiting, blood/mucus in stool, fever, abdominal distension, or poor feeding.