Thanks for query,
It seems that you have got absolute constipation
Take strong laxative to clear your full loaded stool.
it is possible that you might have partial int obstruction as severe pain
and abdomen is swelled.
If require go for ultra sound
Go for Enema.
Take plenty of water,green veggies contain more fibre.
If constipation associated with vomiting then consult surgeon to rule out complete intestinal obstruction
Manual removal of hard foecal stool may required.
Ok and bye.