Hi Andersons,
Sorry you are dealing with this. Fistulas and abscesses are a pain in the butt...literally. I am not a doctor, but I will share a little of what I know from my experience:
You do want to keep the thing draining. If it is draining properly, usually there is no pain involved. If your husband has pain, then he may have some inflammation/ infection building up. Cipro and Flagyl (antibiotic combo) is usually prescribed to keep the infection out and works really well. Doctors usually start with a 2-4 week course ( 1 week may not have been enough). However, when I would stop taking the antibiotics, the inflammation would return quickly. So, unless your husband wants to stay on antibiotics long term (some people do this, but it wasn't for me), there needs to be another option.
Asacol will not do anything for the fistula. Your doc is right, Humira or Remicade are about 50% successful in healing fistulas. Remi did not work for me and I ultimately ended up having two surgeries to heal mine. But I think that most doctors would like you to try Remi or Humira before resorting to surgery because there can be some risks involved. After two surgeries, my fistula is mostly healed, but I do have mild incontinence which may be form weakening of the sphincter muscles due to surgeris, I am told.
Good luck to you both...hope things get better for you.