Pain/discomfort left side below ribs.

I have been experiencing a dull, constant discomfort on the left side of my abdomen and lower back for the past few weeks. The pain shifts slightly — sometimes under the left ribs, sometimes around the side, and now more in the left lower back near the spine and side. It feels like a muscle-like or pressure-type pain, not very sharp, but constantly noticeable. Additional details: * The pain gets noticeable when sitting for long or bending * Passing gas sometimes gives relief * No fever, vomiting, or appetite loss * Urine is normal, no burning or blood * Stools are sometimes sticky and smelly, but I can pass them regularly * I had mildly elevated bilirubin earlier ( 2.08) on 14th sept and it is 1.4 tested around 28th sept * I stopped alcohol for the last 30 days * I occasionally feel an empty or crampy sensation in the upper abdomen Currently, the pain is constant in the left side and middle as well or upper side, Please suggest if I should get an abdominal ultrasound or any tests.