Can a kidney stone cause a bruise on l lower back? I was told I had one and think I’m passing it llq pain mostly under ribs and low back pain on left. Was told I have a UTI as well

Kidney bleeding? Bruising of the flank can result from internal bleeding near the kidney, which could cause pain similar to kidney stone. However, a stone itself is not likely to cause bruising. This could be serious: contact your doctor ASAP. If not seeing a urologist, ask your doctor about possible referral to one. Good luck!