Liver cleanse overload on immune system?

I wonder why, even with colon cleansing, I generally get a cold or feel "run down" for two weeks after I do the liver cleanses. I am guessing that I am releasing viruses that are being stored in the congestion in the liver. Am I way off base?? By the way, after the 2 or 3 weeks, I feel better than ever, but it is rough to always face that "sick" time period!
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