This has been happening to me FOR WEEKS!!!! It's horrible. I had other symptoms of low potassium, so I had my levels checked and they were low. So I got put on a special diet and it has worked wonders.
Lots more water...like a lot more.
3 cups of plain yogurt a day (plain yogurt has a higher po count than others, idky)
4 bananas a day
Baked Potatoe, with the skin (I do this 4x a week)
2 glasses of OJ a day.
Good Luck, and I hope it gets better.