Thanks for the plug for the disABILITIES Board.
At Disney parks, the rides that have any warnings or restrictions are marked with a red triangle warning icon on the park maps. They also have a sign at the place where you would enter the line, at various places in line and before boarding, so you shuld be able to find those rides fairly easily.
Here's a list from the park maps:
MK
Splash Mountain (it's not bumpy, but the drops might be a problem)
Big Thunder Mountain RR
Space Mountain
Tomorrowland Indy Speedway (the problem there is that you frequently get bumped by other cars that come up too fast behind you)
There is no warning for Haunted Mansion, but some people with neck problems find it uncomfortable during a prt while your "doom buggy" is going backward down a hill and the neck is against the hard plastic car back.
Epcot
Body Wars
Mission Space
Test Track
Some people find it uncomfortable on Spaceship Earth when the car travels backwards down an incline, but the ride itself is very smooth.
Studio
Rock N Roler Coaster
Tower of Terror
Star Tours
AK
Primeval Whirl
Dinosaur
Kali River Rapids (actually not bumpy really, but I think the drops are the problem)
Kilimanjaro Safari (this is a bumpy ride on roads that are themed to be "dirt" roads in a wilderness area)
Hope this helps.