If this is your first cleanse, and if you eat a Standard American Diet, the chances of your being clean in 3-4 days is slim to none. At 3-4 days, the detoxing is just beginning! I've done a number of cleanses, and yes, there are days when eliminations will be pure liquid. Hang in there, though, and you may be surprised at what makes its way out in the days to come!
That's my input based upon my experience and that of others I've read on this forum over the past two years.