My husband lost three feet of colon in a resection ten years ago. Stage IIIa colon cancer. Like some of you here he had frequent loose to runny stools ever after. Doctors seemed to think it just goes with the territory and didn't give it much thought.
Ran across a new dr. who checked his gut flora a.k.a. microbiome(?) and it was not right.
She told me to get 'Align' probiotic 14 day package and it did the trick. About $30.00 at small town pharmacy. If you try it be sure to check the expiration date (my pharmacist told me so)
Husband doesn't have to take it all the time, about every 4 to 5 months his stools start getting a little sloppy and I get another box and presto chango all is well again.
Seems he can't maintain healthy gut flora no matter what he eats. Don't know why - was it the re-section or the frequent PET scans following.