A 2 year old boy presents to the doctor's office with poor weight gain. The doctor saw the child three months ago and when reviewing the growth chart with today’s weight and height, the weight has dropped almost two percentile lines and the height has remained the same. On history, there is a few weeks of foul smelling diarrhea, vomiting, and the parent reports that the child is often hungry.  On past medical history, the child is healthy.  The immunzations are up to date. There is a family history of an aunt with stomach problems and a cousin with depression.  On social history, the child has a a single parent.  On examination, the child has no fever. On general inspection, the child appears unwell, and seems to be irritable.  Examination of the mouth demonstrated dental enamel defects.  On ausculation of the lungs, clear breath sounds were heard bilaterally.  The cardiac examination revealed a soft 2/6 murmur.  The abdominal exam showed a distended abdomen. Examination of the extremities was found to be normal.