i/o error ext3 journal

I have a 500Gb external disk (esata) used a part of a backup cycle. I tried to mount it for the next backup cycle and an i/o error was detected in the ext3 journal. I fixed the bad block but that lost the data in the block and ran fsck.ext3. This resulted in a damaged file system message and a scan of the disk and fsck finished ok. The disk mounts rw. I am not really sure if I should reformat this disk. I have copied the backups off the disk and in any case there are later backups. Reformatting is not a problem but takes time and I would prefer not to do it if it is not required but I want a clean file system

openSUSE 11.1 X86-64

Thanks

fsck will tell you reliably weather or not the file system is clean.

run it again if not sure.

If you are concerned about the disk itself run some disk checking utilities