You can have obstructive symptoms form gallbladder issues, but they are upper GI, not anywhere near your pouch. Tailbone pain would be related to pouch issues, arthritis, and/or spinal issues.
My severe tailbone pain was related to a presacral abscess. It had been tender ever since the delivery of my nearly 10 pound son, but nothing like the red hot poker feeling of the presacral abscess.
Jan