Meconium is the stool-like substance found in the intestines of all newborn babies. When a baby or fetus is found to have overly thick meconium that blocks the small intestine, it is called ‘meconium ileus.’ This is found in about 15-20% of babies with Cystic Fibrosis. Some of the symptoms caused by meconium ileus include: vomiting, bloated abdomen and failure to have a bowel movement. It can be treated by enemas or medications. Rarely, surgery is needed to remove the blockage.