What can cause frequent stomach pain that lasts till diarrhea 8hour after I eat chicken?

Food sensitivity. While poultry can have bacteria such as salmonella, since it's happening every time you eat chicken, it's likely you have developed IgG antibodies to chicken if it's happening every time. This isn't a true food allergy and if you go on a chicken rotation diet, you should be able to safely consume chicken in the future. See a doctor who does food allergy testing for advice.