Most Helpful Girls
Hi! Are you using the latest version? The ability to update questions was just introduced to the app so be sure to update to the most recent app version.
Once you do that, just visit your question and at the bottom (where you would normally add an Opinion to a question) you should see a text box that says "Add an Update." Just type in your update and then hit the purple arrow to send it. :)
Most Helpful Guys
Sadly nor have I. Don't think is possible... :-/
Use the update feature