Right sided abdominal pain can be caused by the appendix, inflammatory bowel disease, irritable bowel disease, as well as non-GI causes such as the kidney or a hernia. With a negative CT and colonoscopy, this would eliminate most of the lower GI causes as well as the appendix and hernias.
You can consider a small-bowel series, which can evaluate the small bowel for Crohn's disease - which is a type of inflammatory bowel disease. The kidney can be evaluated via a non-contrast CT looking specifically for stones. An ultrasound can also be ordered.
The prostate is indeed a possibility as well if all the other tests are negative. A transrectal ultrasound can be considered to evaluate for any prostatic abscesses.
The diverticula normally does not cause pain, unless it gets infected or inflamed (diverticulitis). If this was the case, it would have been commented on the CT scan.
You may want to discuss these options with your personal physician.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Kevin, M.D.
Medical Weblog:
kevinmd_b
Diverticulars are a sign that you are constipated or have been really constipated for an extended period of time. You may want to have him go on a no sugar/no yeast diet for about 2 months along with plenty of water and fibre (sounds harsh I know).. Colonic Hydrotherapy will help there as well strengthening the peristalsis of the colon making it able to sustain some regularity. 90% of diseases and illness can be traced to the colon, therefore its likely the culprit.
Another great thing to do that is incredibly affordable is buying potters clay and using a rolling pin to make a large pancake of clay, lay it on his abdomen for about an hour each day for a week and see how he feels. You might want to use a heating pad or hot water bottle to keep it warm because the clay is cold. The clay costs about 20 bux CDN for about 44 pounds so its dirt cheap and can be used on any area of the body. It draws toxins from the area.