Question about recommendation letters!

<p>I've just decided my three recommenders from school a few days ago and told them that I wanted them to help me with my application and write recommendation letters for commonapp. However I didn't expect one of them to complete the letter so quickly! I had something that I wanted to share with them that they didn't know about me, and I'm afraid that he probably didn't mention things that I really wanted to highlight in my recommendation letter.</p>

<p>I just want to know are recommenders able to change their submitted recommendations at this stage? If it is okay then I will send him an email telling him more about myself.</p>

<p>Can anyone help me with this question?</p>