Is the person being poisoned by the air or by the food?

Can it be a reaction with the poison and some sort of food? Since 2011. - sometimes a huge pain near the stomach. - sometimes a period of no pain. - a pain if you try to pick up something on the ground. -pain in the nose -Heartburn -weakness. -your bowel is working well and suddenly you have diarrhoea. - your belly is sensible to touch etc. And near the stomach in the bone you have pain if you press it. -you dont have strength to do nothing -sometimes difficulties to breath -It's almost home but you can have it outside, - Sometimes you sweat a lot in the street and want to vomit, the sweat smell ammonia or sulphur. Is the person being poisoned? Which exam to detect it ? Thanks.