Stage 2 (Day 3 To Day 7) The body embraces the fast and the digestive system is able to take a much-needed rest, focusing all of its energies on cleansing and healing. White blood cell and immune system activity increases. You may feel pain in your lungs. The cleansing organs and the lungs are in the process of being repaired. Periodically, the lymphatic system expels mucoid matter through the nose or throat. The volume excreted of this yellow-colored mucus can be shocking. The sinuses go through periods of being clogged, then will totally clear. The breath is still foul and the tongue coated.