Twitter Bootstrap Button Text Word Wrap

Try this: add white-space: normal; to the style definition of the Bootstrap Button or you can replace the code you displayed with the one below

<div class="col-lg-3"> <!-- FIRST COL -->
  <div class="panel panel-default">
    <div class="panel-body"> 
    <h4>Posted on</h4>
    <p>22nd September 2013</p>
    <h4>Tags</h4>
    <a href="#" class="btn btn-primary btn-xs col-lg-12" style="margin-bottom:4px;white-space: normal;">Lorem ipsum dolor sit amet, consectetur adipiscing elit.</a>
   <a href="#" class="btn btn-primary btn-xs col-lg-12" style="margin-bottom:4px;white-space: normal;">Lorem ipsum dolor sit amet, consectetur adipiscing elit.</a>
   <a href="#" class="btn btn-primary btn-xs col-lg-12" style="margin-bottom:4px;white-space: normal;">Lorem ipsum dolor sit amet, consectetur adipiscing elit.</a>
           </div>
  </div>
</div>

I have updated your fiddle here to show how it comes out.

You can simply add this class.

.btn {
    white-space:normal !important;
    word-wrap: break-word; 
}