Hi getting_old
Another approach could be to cut out (added) sugar, and refined foods and drastically reduce concentrated carb foods like cereals, bread, potatoes, pasta, rice, flour, pastry etc and to increase the amount of low fat protein in your diet rather than increasing your fruit and veg to more than 5 a day. I usually eat porridge or muesli most mornings ( but not always) but other than that most of the time I don't eat the other foods or rarely except when going out for meals and Christmas etc. I eat 1 or 2 eggs for breakfast usually, and lots of low fat yogurt, cottage cheese, smoked salmon, lean chicken, fish, nuts etc and this has slowed down transit as protein takes longer to digest. I do also eat a fair amount of fruit and veg - probably more than most people but you might find that increasing your protein at the expense of the carbs could help? Perhaps try for a few weeks and see what happens? Obviously the gut needs to settle....
Hurdity x