My 19 month daughter likes taking her dirty diapers off and playing and smearing it everywhere I've tried everything from onesies,sleepers,and even took advice from a friend to use ducktape on tha flaps nothing works dr.says she like tha texture I'm stuck?

This isn't anything I haven't heard before, but not for a long time. The doctor is right, you will have to wait till she grows out of it or until you find a foolproof method which she can't get around. Small children like playing in mud because the texture satisfies them, this isn't any different to her. She doesn't realize its not supposed to be done because after all, how can you explain it to her at l9 months old!

Tick

Have you thought about making some goop for her to play with...

Mix up some cornflour and water, you can add a little food coloring too... she will most likely love playing with it and squelching it in her fingers and it will keep her out of her diaper, best part is if she gets some in her mouth there is nothing nasty in there.
When my little brother used to play with it we jut got plastic table cloths and put them on the floor, or put him outside on the grass/concrete and hosed it off afterwards.

You could also try finger painting... same thing but just buy some non-toxic paints and some large sheets of paper... then you also get to keep her artwork as well :)

Its normal and I agree with shaz, get some goopy stuff to play with. Play dough, etc. there are lots of recipies for different textures of goop online :)