If its spicey food that can be severe heartburn or if fatty food it could be your gallbladder. To elviate your worries its best to see a GI doctor. A GI doctor can do tests to rule out what its not and find out what it is.
I would recommend that you seek a doctors care to check everything out- I know it's scary, but not knowing doesn't make the problem go away- it will only get worse. If you seek medical care, you can come up with a plan to address your concerns and what ever the issue is- so get to a doctor and let the know what's going on. Best of luck to you and let us know how you are doing!
I am glad to say my issues with losing weight and severe diarrhea was C Diff or Clostridium Difficle. It is a Healthcare acquired infection. I most likely contracted either in the hospital, surgery center or doctors office. The bacteria toxins are worsened by large amounts of broad spectrum antibiotics given. Only time I had a antibiotic like that was when I had my GB surgery. I was finally diagnosed with C Diff in Oct 2015. I still have issues with bile acid diarrhea that happens after GB removal but take a strong probiotic that does lessen the times I go but keeps my stools formed and not runny. As for your symptoms I am not a medical expert but it seems like Gallbladder or Ulcertive Colitis which could give you symptoms like yours. I would see your Primary Care doctor first then if needed bevrand get refered to A GI doctor as soon as you can. Best wishes in your health.