What Causes Chronic Diarrhea Years After A Colonoscopy?

I am a healthy 69yo man, active, golfing 4 time a week and plenty of exercise, plus a reasonably good diet.
However I have very loose stools every day. Very regular timing, first thing every morning, but could be a problem if I can't get to the toilet!! Only go once every day.
Some years ago a routine colonoscopy showed some diverticulosis.
I have always been soft and regular and loose stools have just crept up over last 6 months. Should I get this checked out?
Thanks
Owen Blockley