fit for a second and memory totally collapse for seconds

dear sir my name is binit sharma and 32 yrs male. my problem is that i sometimes get an fit for a seconds at that time i forget every thing for a seconds and also my vision become nil and cant see anything but can reply every answer to question.before getting attack everytime i feel something like a gas in my stomach and also feel like to drink water after drinking water i get attack.and suddenly get attack and fall down without having control over body. it happens any time any where sometimes after 1 months,sometimes after 10-155 days but after attach after seconds i become normal like nothing happened. please help and let me know what is this. thanks.