It sounds like a pinodinal cyst. Prolonged irritation & pressure on the coccyx,
even just prolonged sitting may predispose people to this.
You should see your doctor for it. If it is indeed a pinodinal cyst he/she may be able to drain it by simply squeezing it (painful!) or by surgery,preferably laporoscopic - least invasive and less complications-, or marsupialization.
Hello - Thank you for the response - I have had a pilonidal cyst in the past (I did not see a doctor but the cyst drained naturally and I have had no issues with swelling around the pilonidal sinus for over 6 months)
This incidents swelling and air pocket are felt about half way down on my left buttox, about 3 inches lower than the pilonidal sinus and only occurs on my left side. Sometimes the swelling results in a visible ball/lump as well as a hard strip of swollen tissue that runs along the left side of my buttcrack (about 1/2" wide and 3-4" long) which is completely numb.
When I cough, sneeze or laugh I can feel the air/liquid move, The air/liquid also makes gurgling noises if the area is pressed on.