One of my patient's granddaughter 4 months old ,only on breastfeed was normally passing 3-4 stools a day, one month back she did not pass stool for 10 days. Otherwise, child is active, taking the normal feed, passing the wind normally, was given Bisacodyl pediatric suppository and then she passed copious soft stools 3 times. Again she did not pass any stool for 7 days and passes on 8th day without any medication. Her Thyroid profile is normal , Hb is 9.4gm, sonography abdomen normal.

Now again she is not passing stools. What can be the cause and how to treat such cases ?