Focal discomfort left side of abdomen about level of last rib that feels better if i apply pressure to it. what is this?

Duration is key here: The area you describe is the location of the splenic flexure, the spot where your colon makes a right turn and heads down toward the rectum. It can often be a place where feces gets hung up briefly and causes pain. But it should pass within 12-24 hours. Something that lasts longer could be trauma (which you would know about) to the spleen area; less likely stomach issues. OK to watch a few days.