You are most likely using non-standard features that are only supported in IE (and perhaps a few more, depending on the feature).
If the page only displays as intended in IE, the code is incorrect and relies on non-standard features or rendering errors in IE. IE has several rendering errors that no other browser has, which makes it less suitable as the first stop for testing. If you build a page for IE, it's almost a guarantee for it not to work in any other browser.
To make the page render correctly in all browsers, you need to first make it work in a browser that follows the standards more closely, like Firefox. Trying to get other browsers to emulate the same rendering errors that IE has would be very time consuming, and doesn't give a robust result.
You might need some extra tweaks to make it render correctly in IE, but this can usually be accomplished in a standards compliant way, for example by setting a specific size on certain elements.