Because they can absorb high quantities of fluid, incontinence pads should never be disposed of by trying to flush them down the toilet. This will cause a blockage and, in the end, the toilet will overflow.
The most recommended way to dispose of incontinence pads after their use is by placing them in a disposable bag, or a nappy sack, and then throwing them in a regular garbage bin or sending them to local waste collectors. Unless there are medical considerations that impose other measures for disposing of incontinence pads, this is the surest method you should employ.