I found that the Psyllium did help to bulk things up a bit but now I am having trouble with it giving me gas which did not happen the first few months of use. I haven't used imodium or lomotil because I don't have diarrhea but have thought about it for the clustering which gets excessive with me. I have to strain a lot sometimes and am concerned the meds would make that worse.
I would also love to find something to reduce the clustering. I am currently on an antibiotic which is giving me loose BMs. You'd think that it would all come out at once but no, even the loose BMs cluster. I went all day Saturday and finally did a tap water enema to stop the nonsense. I did another enema last night so I could work today.
Sorry, I'm no help. I'm just another person looking for that magic substance to make the current normal a little more normal.