it is unlikely that the primolut was related to your gastric symptoms for two reasons. firstly, if generally does not have that side effect, and secondly, because you were using the medicine for a few days and tolerated before, so it shouldn't suddenly start causing these problems. I would guess that you may have gotten a stomach virus, or some food poisoning
. if that is the case, the symptoms should resolve in a day or two. you should rest, drink as much fluid as you can, and you can continue the medicine as prescribed. if the symptoms get worse or do not resolve, you should call your doctor. I hope this was helpful, if you have any more questions please feel free to ask me.