How to repair the file system within in a ISO file

[Shawn Badger]

So I ran into this problem the yesterday and Google has yet to reveal
the secret of how to fix it.

I have a disc that someone else burned that is has some errors on it.
The source is gone so I cannot just simply reburn the disc :(

I was able to use ddrescue to get an ISO image of the disc created,
but when I went to burn that it just replicated the error to the new
disc.

Does any one know how to do an fsck  (or similar) on an ISO image?

I tried just doing a fsck -y disk.iso , but it just comes back like I
used a bad option and I can repair it while it is mounted.