My toddler has bath-phobia!!?

My 16 month old daughter has generally done well with bath time. I put her in the big tub full of lukewarm water and she'll happily play with her toys as I wash her hair and body. Obviously I struggle to keep her seated as she is a little explorer like all kids her age! :) But the last several times (including tonight) she has begun to became very agitated, upset, and clingy when I put her in the tub. She wails and grabs onto me, making it impossible for me to wash and rinse her properly. I try to sit her down and she only pops up and is more upset! At first we guessed that it was a bad diaper rash that was irritated by the soap and water, although now that it has cleared up but the behavior continues. I'm wondering if she has somehow been spooked or has a bed memory of a bath that I'm unaware of. I tried using a different bathtub tonight, to no avail! I hate seeing her act this way, but I can't just stop bathing her!! I wonder if anyone else has had to deal with this sudden bath-phobia and how did ya'll handle it! I don't know what else to do!