Hi - I Am 60 And Have Had Stomach Sensitivity

Hi - I am 60 and have had stomach sensitivity most of my life. Always been diagnosed as IBS. Over last 5 years it's been getting steadily worse and is related to stools always tending to be diarrhea although it's rare that I go to the toilet more than twice a day. Once every two days is more usual - but always with very loose stools - bordering on diarrhea. The discomfort tends to be located in the solar plexus area and is general rather than acute, but more or less constant. I also feel generally unwell and often somewhat dizzy. I eat a fairly low fat diet. They have recently found a small stone in my gallbladder. A private doctor says I should have the gallbladder removed but my GP doesn't agree and although I was offered an operation to have it removed on the national health she recommended against it. One of her arguments is that having gall bladder removed can worsen effects of IBS. Would be interesting to hear your thoughts. Have had various gastroscopies/endoscopies over years and only find mild gastritis.