My Partner Was Circumcised Under General Anaesthetic Five Days Ago.....everything

My partner was circumcised under general anaesthetic five days ago.....everything went fine,no complications.....however,five days post op,he is now struggling to pass urine,stomach very distended and has not passed a b.m either.....he has taken senna for his bowels, but now he is really struggling to pass any urine what so ever.....this has only started happening today.for the last four days post op,he has passed urine without issue....looking for advice please!!