I have had 2 of those drains put in....the most painful thing I have ever experienced! The morphene does not work and that is what they insisted on both times! I hate to be the bearer of bad news but I don't think this will get rid of your abscess. They will say that it will (my surgeon stood at the end of my hospital bed and told me that this is just the way that they drain them now), and the ct will eventually show that it is "gone", but my experience has been this. Once the drain was removed, a few weeks later it filled back up and broke through the skin (mine wasn't a deep abscess) and drained, then healed back over. This happened a few times in the matter of about 8 months. Then I got so sick, and in so much pain, that I went to the er. My surgeon wasn't on call, so I got another one (who has been trained at the Cleveland Clinic), which was really a blessing in disguise.
The new surgeon told me that you can't drain abscesses that way, instead you need to go into an operating room, drain the abscess cavity, CLEAN it out, and then leave it open to heal from the inside out. He went in and did that, and I have never had any trouble with that abscess again.
It makes perfect sense if you think about it....the drain that you have in there can in no way get all of the microscopic infection out, so once the drain is pulled, and it seals over again, the abscess is just going to start filling up again.
I wish you the best. And I hope that things start improving!