There isnt anything wrong with going twice a day, many people do. What is something to watch out for is a CHANGE in HABITS for more than 2 WEEKS. You describe changes for a week or so, keep an eye on it. If it settles down then it was probably nothing, if it doesnt go, or if you notice any other things - especially any blood being passed then its important to go get it checked out.
Also clinically diarrhoea is determined by weight, not consistency (I think its more than 400g stools average per day (assuming you normally pass an average amount - some people just **** more than others))