My 18-month-old son loves the water but he hates when I wash his hair. He fights me every time I rinse out the shampoo. I have tried bands and hats, but I can't get him to keep those on long enough for me to rinse his hair. Could the reason be because he's had tubes inserted into his ears and numerous ear infections? We do put ear plugs into his ears to keep the water out and he has no problem with those.
It's not the ear infections that's the problem -- it is the age. Many toddlers protest invasion of their space--some protest toothbrushing, others protest haircuts, and stil others go on strike when it comes to diaper changes (a real challenge!). Make it clear that rinsing hair is not negotiable. Try to include him in the experience -- have a cup that he can play that he can use to pour water over his head. Whatever you come up with, it has to be done -- with or without a fight. Eventually, he will decide to let you do it.