What Causes Explosive Diarrhoea Along With Flatulence On Intake Of Food?

I had a severe episode with a stomach virus a month ago, after a week was feeling ok. 5 days ago, began explosive diarrhea, only after I eat, lots of gas, minor cramps. After 2 doses of Imodium the stool changed from liquid to formed, but now is ghastly yellowish color.