This is problem with these flushes. The oil can cause the gallbladder to contract and cause a stone to lodge in the ducts. I prefer bitters and lecithin, which dissolves stones that are present and prevents their formation.
The oil does not cause the stones to form. The most common reasons for stone formation are gallbladder stagnation and high cholesterol secretion with lack of bile.
Stagnation can occur for various reasons including lack of dietary fats and progesterone.
Elevated cholesterol secretion most often occurs from estrogen. Lack of bile can occur from lack of lecithin or lack of dietary fiber.