Hi The belly button or umbilicus is the site where the umbilical cord was attached. This is cord that would have transmitted blood and nutrients from your mother to you when you were in the womb. During delivery the cord is cut and the umbilicus or belly button is the part of it that remains. Abdominal pain can occur from any organ in the abdomen from the skin inwards- this includes the stomach, small and large intestines, liver, gallbladder, kidneys, spleen, pancreas Pain can be due to infection, trauma, inflammation, blockage, allergies, cancer Crusts form outside the eye during sleep because the limited eye movements during sleep allows build up. Hope this helps