I ate fish cooked. 3 minutes later I started feeling bad and I had to rush to the toilet. I had a pretty serious but intermittent diarrhea without vomiting. Could it be food poisoning? Is there anything I can do?

It is unlikely that the case of food poisoning as the causative agent usually takes 4-12 hours to produce symptoms. It is probably caused by chemical irritation of the intestinal lining . The body works well when trying to remove irritants . However, the fish is not cause diarrhea . Whatever it was that irritated the lining of your intestines increased frequency of bowel movements causing a faster expulsion of the contents in feces - causing therefore diarrhea.