Have you started weaning? That can alter bowel habits.
Does your LO seem to have tummy pain or are they in pain when they go, or have a bit of blood when you wipe? If so they could be constipated. It's normally really easy to treat by extra fibre in the diet, offering water with meals, and sometimes the doctor can give you something like lactulose to help. Most babies grow out of it with time once their gut matures a bit, my LO was often constipated when I started weaning but not now. Xx
Ps if the altered bowel habit doesn't seem to bother them, I'd just keep an eye on it but I wouldn't worry. X