If you want to improve the fibre content of your intake save a lot of money then buy bulk psyllium powder from a heath food store or similar. It is the active ingredient of Metamucil without the added sugar, artificial colour and flavour at about half or one-third of the price.
Psyllium is widely recommended for those with diverticuli in their gut as keeping up the volume of fibre reduces the chance your diverticulosis will become diverticulitis. You will need to experiment a little to get the dose right.
@syncretic Good advice. Thank you. @mark_m Prior to using Metamucil, I was not “regular” in visiting the bathroom. But am now “regular”. I have no doubt that I need supplementing my fibre content. Of course that does not mean - as syncretic indicates- that it needs to be a commercial product.
In my view increasing your fibre intake is good overall for your gut health as well as dealing with constipation. Start with ensuring your diet has plenty of vegetables and add bulk with bran, psyllium etc as required. If constipation persists see your doctor
Fibre is not likely to have any side effects, or serious problems in excess dose, which may happen with magnesium, so fibre is preferred in my view. If in doubt ask your doctor.
In answer to your question @Jon01, we had a look at some of these supplements from the point of view of reducing blood cholesterol. However, I understand you are probably after more comparative testing, and I will pass on this request on to our testers.