Are you on a low carb diet? I had this problem a few months in. I now add Psyllium husk to my breakfast and ground Flax seed to my other food. I also make sure to drink way more than I used to.
Funnily enough I had this problem a few weeks into LCHF. I also had a problem with hunger at the same time and the answer to the hunger problem also solved the constipation problem. It was, for me, creamed decaff coffee.
Thanks a lot great ideas shall give some of them a try have upped how much I'm drinking a lot and seems to have helped a bit but will give the seeds a go