Pain right under my right towards the center.?

I had my gallbladder removed a year ago this month. I've noticed off and on for the past year and especially lately, I'm having pain right below my sternum towards the right side, under my . It's a dull, aching, feels like a knife........type of pain. Nothing severe. And for two weeks I've had diarrhea.......but not severe either. I'm eating and drinking fine and I'm not losing weight, so should I be concerned? Is it maybe IBS or something?