For peace of mind ask your doctor.
Since this is new for you, it might be something to get checked out by a gastroenterologist.
If you have recently been on antibiotics, you could take a probiotic and see if that straightens it out.
Try stopping milk or any new food you have introduced, such as sugar-free products. I think it might be a bacterial bug, which is why you may need to see a gastroenterologist.