What Causes Bloating Sensation,pain And Gastric Problem In Stomach?

I am having a lot of stomach bloat, pain and gas when I sit down for more than 20 minutes. I had this happen in mid-Jan and a couple of days later, I had a miscarriage. The first time it happened it was approx. one week after my period and this time it is towards the end of my period. I have had endometriosis in the past. Could this be a sign of regrowth?