Lovely topic, I know. But a common concern amongst us parkies, especially those of us who are heavily medicated. I've been having trouble with constipation for quite a while. Even had an emergency room visit (which was SUPER lovely!). I was even starting to think I'd better push for DBS so I could cut back on my meds before they cause me permanent bowel damage, even though my symptoms are mild and pretty controllable at this point.
Anyway, a new friend suggested that I start each day with a glass of water and some fresh fruit. So now, for about the last three weeks, I've been washing my meds down with a pint of water and eat an apple, banana, some pineapple or (my friend's personal favorite) two whole kiwi fruits. I'll spare you the details, but I am happy (VERY happy, actually) to tell you it is working great! Regularity seems possible!
Thought I should mention it here.
One More note: I was also surprised to learn that coffee does NOT help with constipation as I always thought. In fact, it could help CAUSE it (or, so I'm told by my friend and my own research). I'm still drinking coffee, but not as much and not until I've finished my meds-water-fruit routine.
Hope it works for you.