I got EC after I completed a course of Antibiotic treatment for strep throat. I think anxiety had something to do with it as well and possibly in turn hormonal imbalance.
Other than that cold be an allergy, deficiency, trauma induced, or digestive issues.
I would look at lees, MontrealHomegrown, and Warriorqueens posts all who overcame this by changing their diet. This isn't necessarily your cause but would probably help either way. Also, try to remember if you made any changes in your lifestyle before this happened. Change of toothpaste, shampoo, certain foods, medications etc..
As far as Liver Flush goes, I haven't done one so can't give much insight but probably will in the future. Just be careful with them as they are potentially dangerous to do.