I have had problems having a good flush and often the purge would not start until late in the afternoon. Clark wrote that some people don't have a purge because they are deficient in magnesium and the body uses it to correct the deficiency and so water is not attracted into the bowel. But I kept having this problem and I think that it was because I had so much swelling and inflammation in the small intestine that the purge was very slow. My underlying cause of the small intestine congestion is Celiac Disease, Leaky Gut and food allergies /intolerances. What I eventually learned to do, besides being strictly gluten free, was to take a laxative the evening before, then the next day I would drink prune juice and/or water - no solid food - and use a herbal laxative and strong peppermint tea. During that series of flushes it became less difficult to purge as I eventually got thousands of stones out.