One stool per day in morning two hours after waking but always unformed, mushy and fluffy. tried numerous changes to diet, different types of fibre, exercise, reduced caffeine to no affect over last five years. do you think any solution is possible?

Yes: Fiber is the answer. Even though you mentioned fiber trials, I wonder if you took enough, and incorporated (non soluble) high fiber foods in your diet Think: kale (chips work too) pumpkin seeds, pop corn, chick peas (hummus is ok), grapefruit, oranges, cabbage, Brussels sprouts). Citrucel is not gassy, but oat bran, wheat bran work well. Bake oat bran muffins with flax seed meal and enjoy daily.