Help please! Constipation after Liver Cleanse

I did my first liver cleanse last Friday night. Got a number of tan stones out up to midday Monday then bowel movements returned to normal. It is now nearly 5pm on Thursday (Pacific time) and I have not had a bowel movement for almost 24hours. I never get constipated but feel I really need to go but when I get to the toilet, nothing happens. Should I take Epsom Salts or do a salt water flush with Sea Salt (from Master Cleanse) or are they the same thing. Have also had sore upper back today.
Help appreciated!