Did you see a Gastro bod in recent years, i.e. since meno started?
As a recovering anorexic my gut stopped working completely, the muscle spasms had stopped in 1991 because I wasn't putting anything into my system so they went to sleep

, I felt SO ill. My GP gave me various medications to encourage movement, i.e. an anti-sickness med (I think
Domperidome [thought I thought that had been withdrawn

] plus something (?Colpermin) to stop any upper gut wind and it worked within days >phew<. Slowly my bowel re-energised so that I became 'regular' which mean there was no longer a back-up which had made me feel so sick. I took this regime for years, always swallowed within an hour of my main meals.
Then I switched to
Actimel several times a day. My bowel felt great and if I get slow transit I start swallowing it more regularly. Mum swears by prunes

. It really is Trial and Error isn't it! and add hormone upheaval to it all

Your GP is probably erring on the side of caution but HRT is delivered in various ways so it might be worth while asking for a referral to the Surgeon who did you 'small op' for HRT advice - although they can be as 'thick' as GPs sometime about what is required!
Do you eat little and often?