Hello Doctor....my Baby Is 1 Month 8 Days Old. Last

hello doctor....my baby is 1 month 8 days old. last couple of weeks daily at evening or sometimes night starts inconsolable crying continuously 4-6 hrs.baby is not taking feed at that moment properly. doctor adviced me to give colimex drops 0.4ml.I gave 1 day then I stopped again after 1 week later again I given. can u pls suggest me how much should take and how many days need to be given. Tried to take burp after feeding but if baby sleeps I couldn't take burp..pls tell me how to burp him while sleeping.