Why does my baby have jaundice and how long will it last?

My baby no.1's jaundice lasted for 8 weeks as it is caused by breastfeeding jaundice, after PD ordered a liver test to ensure it is not caused by liver problem of my baby. PD advised me to continue to breastfeed my child often to flush out the toxic. Her jaundice was cleared without any phototherapy. For my 2nd baby, his jaundice level was very high, reading level at about 400 and was sent for phototherapy treatment for 3 days. PD from Mt. A commented that it could be caused by the food that I have consumed during pregnancy and I suspected it was the cordycerps that I have consumed.