Fairymums point about parents having 1/3 of the time off as non parents is very interesting.
I can see that employers would get peed off if their staff were continually off for childrens illness, or if someone who before they had children didn't take much time off and suddenly was continually off allegedly for their own illness. However as a manager I also know that I am more peeved by those who in my team happen to be single, childless and male who have random repeated five day illnesses just short enough not to require a doctors note.
Someone also made the point about keeping some spare days, I have bought the maximum number of flex days which are reserved as days in case DS gets sick, but I also am lucky enough to have GPs as back up.
I would imagine that most managers in the real world, although perhaps not the super high flying high powered business world that I don't know much about, would be sympathetic to a parent male or female who required the very occasional day off for their childs sickness, if they weren't then I can't imagine many people would want to work for them.
Life happens and if as a manager they had expectations that everyone who works for them would have a 100% attendance record then they are just not being realistic. I returned last week to work and unfortunately on the second day a major family crisis occurred my boss immediately told me to go home, as it turned out I didn't need to, but by her attitude she has gained loyalty from me and a desire not to be off work unless I really have to.