I have churning gas, something coming up in my throat, and diarrhea after some meals. Help! ?

Acid reflux. If it started quickly may be a GI virus or food poisoning. If its been going on for awhile could be acid Redux or lactose/gluten intolerance.
Pain and diarrhea. This could be caused by many conditions including ulcers and infections to name a few. Best to see your physician for examination to find out the cause and then get proper treatment.