crohns and cholestyramine

Hi everybody, I have just joined the site and this is my first posting. Before I start writing my request for help and information let me tell you a little bit about myself. I am a 78 yr old male and was diagnosed with crohns 53yrs ago. During that time I have undergone the following procedures : - I have undergone two bowel resections, I had a abscess in my bowel which I had to have drained, I had my appendix removed
and it was during this procedure that they found that I suffering from crohns, I also had my gallbladder removed. I have had an operation on my prostate, two weeks in hospital with sepsis, and more recently I had to have my left kidney removed since during a scan for something else they discovered that I had a tumor on this kidney. The consultant said that was around 85% certain that it was cancer. After the operation it took another six weeks before the results of the biopsy was back, which it turned out the tumor was benign. I wish to discuss this a bit later as it has a bearing on my requests. Around 17 yrs ago my GP referred me to the IBD clinic at my local hospital. after suffering bad bouts of diarrhea, for a long time. The consultant prescribed B12 injections every three months, which I still have today. He also prescribed "cholestyramine" for malabsorption. which again I still take today. Around five months after taking this medication I developed discomfort in my lower back in the form of a ache. which was located in the void just below my ribcage. Lately it has become worse and radiates up my ribcage and spine. In the early days I had a x-ray and a ultrasound scan. but nothing untoward was shown. I did look at the leaflet that came with the cholestyramine but there were no side effect indicating my problem. Since the doctors were not coming up with anything I decided to do a little research my self via the internet. After much searching I came across a site that gave me some answers (see link) )https://www.drugs.com/sfx/cholestyramine-side-effects.. Now I am not sure if this link will work since it is not highlighted after copying it from the address bar. The site that this page came from was "Drugs.com" And the side effects of cholestyramine. The problems that I am experiencing is under the sub heading MUSCULOSKELETAL. where it refers to back ache etc. But another item of information from this page which gave me more cause from concern was at the start of this page where it indicated when carrying out trials with cholestyramine on rats it caused tumors, but they went on to say that they had not checked this side effect in humans. But as I told earlier I had to have my left kidney removed due to a tumor, it makes you think. I have forwarded this information to the relevant authorities. Finally if any of you have experienced any of the side effects listed here I would be grateful if get back to me. Thanks