For a few days I've been having waist area back pain on my right side. Last night I became constipated, which passed in the morning. When I went to the bathroom today, my urine color can best be described as 'dark orange', but there was no pain involved. After I urinated, I instantly felt a change. Back pain has eased up significantly and I feel somewhat better. Is this a symptom of perhaps passing a small kidney stone? I'm 75 years old and recently I have discontinued drinking as many juices as I normally do and haven't been hitting the fruit as much either. Other than that, no change in diet. I recently moved from an altitude of 6200 feet to 4000 feet. I drink filtered water and have the occational soda. No smoking, no alcohol. Had aortic valve replacement exactly 12 months ago. Numerous prescriptions that have never give me problems in the past. Have not be taking vitamins. Any information would help. Thank you!