My employer accepts a Stat Dec in lieu of a medical certificate. Not sure whether that's universal practice but worth checking? Sometimes you are ill enough to stay home for a couple of days but don't need to see a doctor. Gastro is a good example. No point spreading your germs around a GP's waiting room just for the purpose of obtaining a medical certificate!

oh yes! I heard about this at my work recently too!! but I work for the govt so.... maybe different conditions at private companies...