Remember how difficult you thought it was to bathe a baby for the first time? Well, same applies to bathing your elderly. And they are bigger, and heavier, and they may be in pain, have just suffered a heart attack, have difficulty breathing, and a host of other physical issues. And, to top it all off, they may get angry at you for bathing them (though technically a baby may scream too!). They may have dementia and accuse you of being cruel to them and try to hurt them.
There are definitely some things you can do to prepare yourself and your loved one, AND your surroundings for a experience that is not as unpleasant. This article gives you some good tips on accomplishing this: