On Mon, 12 Nov 2012 12:00:54 -0500, "EXT"
wrote:

If her underwear is polyester or any other synthetic, they will not do any
good in the septic tank as the bacteria will not dissolve the man-made yarn,
they could block the exit pipe and cause another back-up or move through to
the leach field and block one of the pipe runs. I would get them out of the
pipe as soon as possible. Do you have any cleanouts that you could open and
work from, or pull the toilet and attack the blockage from the open pipe
without scratching the toilet. The pipe size from the toilet is a minimum 3
inches in diameter. If the daughter is a child, I cannot imagine the
underwear being big enough to plug the pipe, if she is old enough, possible
something else like a sanitary pad attached to them may block the pipe.
Again, I would not let them travel into your septic tank, unless you
immediately have it pumped out.

+1