Abscesses after Pilonidal Cyst removal?

Hey there - about 8 years ago, I had a reoccurring problems with abscesses that were caused by a pilonidal cyst. For a while after it healed, for about 4 years it was good and didn't cause any real problems. They took out a lot of area - sorry for being gross, but the scar is above my butt crack and when they did it it was so large you could fit a large tennis ball in the hole - it has since closed up and as I said was fine. But over the years I began to get abscessing again! Ugh!

I am noticing over time they are reoccuring again and it seems each is worse and worse. I have one right now I am worried about having to go to the doctor for since I don't have insurance... but will go if I have to.

My questions - is this common? Shouldn't most of the tunneling have stopped and why would this come back?

What causes them in the first place?

There really is no main cause for these abscesses. Some people are born with dimples in that area that, for some reason, are more susceptible to infection than others. It was thought that hairs/boils caused the problem for a long time, but that's since been proven false in the majority of cases.
Preventative care is your best option after you've had surgery as they are likely to reoccur.
Keep the area clean at all times of sweat after exercise and take warm baths frequently.
When you feel an episode where you're having pain or suspect reinfection in that area, always go to a doctor to keep it at bay. They can suggest cleansing products that are antibacterial (bacitracin, for one) and if you're in a later stage, they may prescribe an antibiotic to ward it off. Once the infection is in there, it needs to be drained suscesfully so that all infection is out. That's why they sometimes put stints in abscesses...you can't just stitch it up. But the infection can destroy your flesh (gross, I know) and that's why you're left with a whole afterward.
Be vigilant about keeping the area clean, try not to scratch it and keep it as dry as possible after cleaning. Moist, warm areas are really bad for bacteria to breed, thus causing more infection.
Always try to treat them sooner rather than later, as infection spreads quickly and easily in this area, especially if you've had prior infections there and scar tissue.
I know it's tough without insurance, but if you qualify, you may be able to find a clinic in your area that can treat you for a lot less than a regular doctor. Either way, you really need to get in there, have it looked at and keep it from spreading as that's what's going to cause potential issues that may lead to another surgery with draining.
A proper lifestyle including exercise, plenty of sleep, lots of water and a good diet high in fiber and leafy vegetables will help boost your immune system so that these infections don't pop up so frequently.
Get it checked out and good luck.