Hi, If I were your treating Doctor for this case of severe pain under the left rib cage, I would come up with three possibilities, these include: 1.Anemia is one of the common causes of lip discoloration. It is often related to iron-deficiency anemia but any type of anemia can be responsible. Hemoglobin is responsible for the naturally red color of blood. A deficiency of hemoglobin or red blood cells will affect the lip color accordingly. In severe cases this discoloration may be slightly blue and becomes more pronounced with cold weather. 2.Cyanosis associated with a higher than normal level of deoxygenated blood. This can be caused by any number of pulmonary diseases as obstructive bronhitis, pneumonia. Emergency medical attention is necessary if blue or purple lips are associated with a diminished level of consciousness, cold and clammy skin and difficulty breathing. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing your baby good health.