Drainage tubes are not used with liposuction alone. If you are having a tummy tuck combined with some liposuction in other areas, then you will have drainage tubes placed to assist in your recovery in the area of your tummy tuck alone. Check back with your doctor to make sure you did not misunderstand your plan of care.
I never use drain tubes with liposuction. If you have seen a surgeon who is recommending them, I would be suspect as to his or her expertise. You ideally want to see a board certified plastic surgeon with the training and expertise to safely deliver great results.