tomato juice seems to help a few people. Drink the non-concentrate and 100%, read the label to make sure. I say 2 glasses or so, monitor and adjust.
Drink water — I keep reading nonsense of drinking 8+ glasses of water, sure if your 9 feet and 300lbs than maybe. Yes be hydrated but on liquids….that idea that you need to drink a huge amount of water are based on studies from the 60’s I believe. Drink moderately, I say 1L is plenty if you drink other liquids. Water is best but staying hydrated makes the stool softer.
Yes, it is possible to have too much fiber in your diet. If you are taking supplements or things high in fiber. Don’t go overboard with it, eat normally. Supplement as a last result. You will be better off…
Here is a nice video, not a complete list but helpful.