I never had gallstones - what I had was described as 'sludge'- so of course, it wasn't as obvious in ultrasounds. All they could ever really see was inflammation. I had my gallbladder removed and thought that was the end of it; however, I later ended up getting more of that 'sludge' in my bile duct, which then went undiagnosed and led to a septic infection. All the signs were in my lab work, but the ER doc chose to focus on the ultrasound, which didn't show any stones, so home I went (even after arguing and reiterating my history of never having had stones)- talk about malpractice.