Your post doesnt provide too much information to go on, eg what you did to pass what you think to be a fluke, what you have done about the pain you are experiencing in the gallbladder area....liver cleanses? You dont mention your age, diet (vegan/meat eater) so not too much to go on....
However if you suspect that it could be the gallbladder, and you think you have passed a fluke/parasite then perhaps you would do well to work on cleaning up this area ie the liver, and a potential parasite problem.
Once you have accurate information and step by step proven techniques the work is easy to do. To make things simple, I have over the last few years put together a 20 page book that you can download for zero cost that contains the most concise, two easy ways to clean out the mud, stones, accumulated debris cholesterol from the Gallbladder and Liver. (The link to the book is at the top right hand corner of the web page)
It also explains how to easily drive parasites out of the liver using non toxic and entirely natural method. (its shows actual pictures of a liver fluke). Its also explains the difference between a liver cleanse and a liver flush. Big Difference, that few people appreciate.
The book is entitled "Secrets of Liver Cleanse", and is being offered to this community in appreciation for extensive recovery and healing that I have received as a result of what I have learnt and applied from these forums. My wish is that this process could be easier for everyone.
I hope you find the insights you need to be able to resolve your challenge with minimal time wasted.