Thanks for choosin hcm I read your problem in detail and understood completely. Rectal abscess is the collection of you dead tissue, bacteria and blood cells which died in killing the bacteria whic invade that region.....this whole material keeps on collecting until it is surgically drained, there is no way to dry up a preformed abscess yet antibiotics help keep this process static. In view of this i would advisu you to see a surgeon immeiately so that it can be treated and also investigation for Anal fistula needs to be carried out too. I hope you querry is answered.feel free to ask me if you find it difficult to understand.Get well soon