I Am A 46 Yo Female..around 180 Pds. I Had

I am a 46 yo female..around 180 pds. I had my galbladder removed more than 20 years ago, have had 3 live child births last one 15 years ago and had a gastric bypass around 13 years ago. I am having some strange sensations in my left side- not painful, but I swear it feels like something is "moving" in my stomach area. I did have a ulcerated esophogus 4 years ago that was treated after being scoped at which time the doctor who did the scope said my surgery site from gastric bypass looks perfect. I do seem to be having some bowel movement issues, but nothing drastic. What could it be?