Hi,
My Lo done this exact same thing, there was no reason she just decided to hate it!
I got really good advice from here and it was to run the bath and just let her stand in the bathroom, don't try and put in her just let her stand in bathroom while it runs.
Slowly start to play with the water, I used to line her ducks up along the side and push them in, let her join in if/when she wants.
Let her take it at her own pace, With N the first time we done this she wanted to sit on the side of the bath with feet in so we let her just do this. (left nappy on which seemed to keep her calm too??) OH got in bath to show her it was fine too so she was pushing the ducks at him.
It took as about 2 weeks of slow and steady bathtimes to get her used to it again.
Unfortunatley at about 17 months she began to be the same so I repeated this and she is now 23 months and love sit again!!
(I'll see if I can find link to the advice I got too)
x
Link to my old post with advice:
http://www.babyexpert.com/community/forums/thread/1064651
Edited: 09/01/2011 at 10:08