Yes, you can withdraw a submission by removing the Challenge hashtag from the image. To remove the hashtag:
- Select the image you wish to remove (either in your or your ).
- Tap the in the top right corner of your screen.
- Tap Edit Details.
- Erase the Challenge hashtag from the caption.
- Select Save.
The Challenge hashtag will usually start with "#ec," "#pc," "#sc," or "#irc".