While I can't speak directly to your medical situation, I can speak generally about the Liver Flush and its requirements.
To successfully flush the liver, you need to have a GI tract capable of safely eliminating the released material. In other words, the ability to poop without danger. You also need relatively healthy kidney function, to handle any secondary uptake of toxins not eliminated through the bowel. If you use Epsom Salts , the resulting purgative affect is quite dramatic. Epsom Salts also pull water out of the body, into the gut. This can result in dehydration and loss of electrolytes--not great for those with kidney problems or certain metabolic issues. However, you do not have to use Epsom Salts (more below).
The only other significant problem would be having a stent or other abnormality in your biliary system, which might prevent the release of gallstones.
Epsom salts are intended to clear the gut of solids in order to make room for the eliminated flush waste, gallstones, and associated garbage. Epsom salts also relax the bile ducts, allowing for the easy passage of gallstones. Epsom salts also serve a tertiary function, that of contracting the gallbladder. However, many people find epsom salts to be too harsh, not to mention unpalatable. An alternative is to use magnesium citrate, which can be purchased under the brand name Natural Calm, in amounts equal to the original Liver Flush recipe. Magnesium citrate has a much milder purgative effect and tastes sour, rather than bitter. While there is no evidence that magnesium citrate contracts the gallbladder, it appears to relax the bile ducts in the same manner described in the original liver flush. Those wishing to encourage gallbladder contraction can add a teaspoon of turmeric powder to each magnesium citrate dose, resulting in a bitter beverage that achieves the same result. Like epsom salts, turmeric has been clinically proven to contract the gallbladder. I believe this combination is a superior alternative to espom salts, for people wanting to avoid the harsh effects of the traditional method.
The flush mixture itself is completely harmless, barring some allergy to any of the ingredients. Four ounces of oil should be enough to purge the liver (and possibly the gallbladder) of gallstones. Some people increase the amount of oil as they become more experienced with the Liver Flush protocol.
Finally, the use of apple juice and malic acid should be considered optional. Thousands of people have flushed without completing the week long prep described in Andreas Moritz ' book. However, the day-of instructions should be followed precisely, until you are comfortable making modifications. Some people also use water or coffee enemas to remove the flush waste from the colon, rather than the more expensive colonic method. Some people don't do any of these things (myself included).
I hope you find this response helpful. If you are able to poop, you should be able to flush without danger, provided you follow the recipe.