Thank you for writing!
IBS can cause upper abdominal pain as well as lower (which is more common). Constipation can certainly cause upper abdominal pain, as can gas. If this was a once-off occurrence, see what happens in the next few days. If it doesn't stop, you need to be seen. You didn't say what kind of IBS you have (constipation, diarrhea or both) but if you are not having bowel movements, you need to talk to your doctor asap. Please keep us posted.