Yes, a cholecystectomy is likely to complicate issues when working with fasting.
Intervening with a very clean diet and fasting first is likely the wiser choice.
A choice made under peer pressure is not a good one, so do take a deep breath before letting anyone come after you with statistics and the like to try and hurry you into the operating room.
Removing a gall bladder doesn't address issues that can come from pesticides from food and liver congestion from infections.
BUT you are still in God's hands if you choose to set yourself there, and He'll cover you on either side of the surgery. See Psalm 41.
I say that the only way to tell (hos fasting will help) is to start testing by practicing your fasting skills.
Start with the 1 day, eat fruit and veg, a bit later try the 3 day, then the 5 day, and so forth.
You will get the full picture that way.
It's never too late to work on resting your gut and gallbladder, I think that your fasting will have successes.. Just remember it feels scary when gut flora and parasites loose their hold and have to leave the body.
After a cholecystectomy one becomes more dependant upon supplements, not less. GB-3 (a combo of a sulfurous herb, choline and ox bile) is the most important. You'll need to -supplement- bile because you'd be constantly releasing it into the gut.
Anyways, I am indeed sorry that you are facing this current challenge, because it is a puzzle!
In my own challenges, 70% of the holistic health remedies and practices I have tried haven't suited my needs, and 30% made a major change in my life. Fasting, Iodine and prayer/meditation have been key to making progress. I think I've mentioned before, the input I recieve when praying helps guide me forewards in what steps to take.