I took a closer look at the plastic piece that remains up under the lip of the bowl and it appears that maybe it is not broken. There are no holes in it - rather it simply directs some of the water entering from the back of the bowl to go around the side of the bowl to create a whirlpool (albeit a very weak one) effect. I'm now wondering if there is no broken piece but instead the toilet was designed this way. Surely not? It's made by Crane but I can't find the model number on it anywhere. The house was built in 1996-1997 so the toilet is probably about 7 years old. Thoughts? Anyone ever hear of a toilet designed like this?