Newborn not pooing for more than 24h help!

please go to a&e! to get check if he/she is dehydrate. i was so alone when i had my 1st , called three times to the same ward but mention to keep breastfeeding. my husband insist on buying formula and gave my baby , after he cried for so long he was okay for awhile and then cried again till we went for follow up jaundice the next day , just to know he was too dehyrated despite even peeing & pooping. lucky for the followup. hence he went thru drip & also phototherapy as the dehydration make his jaundice worst.