Brownish Sand Like Substance In Urine. Feeling Fullness And Tingling. Discomfort In The Armpits. Any Advice?

I have noticed this morning after my first pee, that it ends up with a hard to push feeling with a discharge of sandy-like brown colored structures. I did urine analysis one week ago and they said I had sand in my urine. Could that be the sand is being flushed out? Also have been having this fullness and occasional tingling, sometimes like needles being inserted in the area right underneath the right rib cage. I fasted for 9 days and it somehow became better but I still feel it to some extent with some back pain. The urine discharge started happening right after I stopped the fasting though. One thing I forgot to mention is that I do feel sometimes some discomfort under my armpits. I have no vomiting or decreases in energy, and am not loosing weight rapidly and for no reason as well.