When I disputed an item (a CO) my scores all went up, if you pull your reports during a dispute, you should see in the "comments" line I believe, something like "consumer disputes, investigation in progress". This will be in your "Accounts" section of your Fico Report within the item/s you're disputing.. In my case during the dispute, the item I was disputing normally had a red flag next to it, indicating a late pymt or a negative of some sort. During the dispute the red flag was gone. And once the investigation was complete the red flag reappeared and my scores went back down.
From what I've read not all disputes are done this way, with some disputes the negative listing stays but the negative impact stops impacting your score during the dispute raising your scores, and other disputes the negative listing and impact to your scores do not change.
This is just from my experience, I hope it helps.
Best of Luck!!
