Suggest Dosage For Ingestion Of Cremaffin

my Dad just had a 2 major surgery colon which spread to liver both cancer parts are removed surgically, doctors prescribed cremaffin to help the bowel movement but, also warned that he should avoid taking it long term, now I'm worried it's been around a month after the surgery and my dad takes it regularly so how long he can consume it regularly ?Is there any healthy ways to help him?