Gallbladder Sludge

I'm 11 months out from a revision to RNY from VSG (serious GERD issues).  I took actigal for six months after both surgeries.  A few weeks ago, I was having some GI issues and after an abdominal ultrasound was advised I have gallbladder sludge.  My GI doc advised me that with sludge it didn't need to come out.  He did send me for a HIDA scan and I'm waiting for results.    I have my year follow-up with the surgeon in early July.  I'm planning on waiting until I see the surgeon to discuss with him unless I start having any issues.  Just wondering if anyone has had sludge and ended up having their gallbladder removed.