Skin abcess(abscess) from Crohn's?

I was diagnosed with Crohn's about 3 years ago.  I went to see my PCP today for a skin abcess (abscess) or boil that is at the top of my bottom.  He said he sees several patients with Crohn's who get these.  He prescribed Flagyl and Bactrim, and advised me to follow up with my GI.  I already have an appointment with my GI later in the week for a check-up, but I was wondering if anyone else has had this problem, or ever been told Crohn's causes them.  I understand fissures, and other problems that occur within the large intestine from it, but had never heard it can cause sores on the outside.  Anyone else?

Thanks.  

[UncontrolledSarcasm]

   Search Fistula. An abcess (abscess) can tunnel its way from the intestine to the outside of your body or to anywhere inside. Mine went from my large intestine through my vaginal wall. I'm not saying that is what your abcess (abscess) did or came from.....but fistulas are definitely sores we Crohn's patients can get on the outside. Because of the location, mine is not treated easily. Others on the forum have had success with treatments ...sometimes surgery.
   I wish you the best of luck with your upcoming check-up.

[coughting]

Yes, it does sound like a fistula.  This is not something that usually clears up without surgery.   You need to see a gi dr and determine if it is a fistula.
If it is a fistula you could have others.  Watch for anything like a bladder infection that doesn't clear up with a round of meds. etc.