Yes, lots of water. Not too long ago, I had constipation even though I eat enough fruits and vegetables. Eating oats porridge in the morning which used to produced smooth and easy passage for the stools, didn't work. Neither did eating dried prunes.
I then remembered my sister's words when I expressed wonder at how anyone can pass motion a few times a day when I have problems with even passing motion once in a few days. Drink lots of water, she said. I did that and my constipation is now history.