Suggest Remedy For Recurring Pain In Upper Left Quadrant Due To IBS

I have upper left quadrant pain from IBS fairly often. I have suffered from IBS since getting amoebic dysentery in the war - 1944 during the invasion of Germany . It is fairly well controlled by careful dieting but I get constipated and after taking medication to relieve it have diaharea. At these times I have pain in the upper left colon particularly when lying down in bed at night. I would like something to moderate the pain but my GP seems to think that at my age it is wear and tare so I have to put up with it.