This is not something that you come across to be honest. Firstly we would advise whilst still within aftercare is to plan a full nutritional assessment with your provider to see if they feel these symptoms are diet related.
I’m thinking could this be an intolerance to the ongoing vitamins? If things have been the same since your surgery – maybe try an alternate?
Maybe speak with your GP, see if they can run an tests to help determine the cause?
This maybe something that is just as a result of surgery and may naturally resolve as time goes on, but definitely worth exploring all the above options to rule them out
Let us know how you get on – not the best symptom n hope things do settle down for you xx