could be a cyst or a fistula as well.
I had something VERY similar to that, similar location, hurt to sit on, to touch and all that, I went to my doc and we figured it a cyst and she gave me meds to soften it or something, not sure what it did, but it did make the lump less painful, smaller and..well then it started to drain and a year later its still draining, we figure what started or we thought was a cyst is now a fistula, not sure yet, need to get my gastro to check. Best bet is talk to your doctor (or gastro), they can give you antibiotics, or if its a soft cyst, they can drain it, and if its a fistula someone else will have to describe what they can do for that since I am not there yet.
26 year old, married. Diagnosed with Crohns at 17, suspected of having for at least a year or so before that. Alot of Crohns in my family history. No surgeries yet. 2 bad Flares so far. Taking Entocort.