Is it Food Poisoning or something else?

I went to Peru on april 8th. On the 11th, I got really bad food poisoning. couple hours after eating the food in question, my stomach hurt realy bad, got the runs, whatever. didn't think anything of it. But, it continued. every single day I was there, several times a day, my stomach burned so bad that it woke me up and I had to use the restroom. i left on the 15th, but my stomach still burns, wakes me up as early as 6 in the morning and continue to have the runs. now i know you might get some sort of shock from eating food in other countries, but shouldn't it be only once, after you ate the food that poisoned you? what makes me say that, is that i was there 3 days before anything of the sort happened, and on that day I did eat chinese food, some of which contained a certain type of pumpkin, which i was told by one of the people i was visiting contains some level of cyanide. now, I'm not an expert, but I've read that (if you don't die) your body purges itself of the chemical as fast as possible. yet, here i am, almost a week after eating it, still in quite a bit of pain and no kind of regularity since. anyone have any idea?