Obtain a full history of
gastrointestinal symptoms (severity of diarrhea and degree of malnutrition)
causing failure to thrive. In rare cases, TPN is required. Evaluate volume
status clinically and check electrolytes, blood urea nitrogen, and
creatinine. If the patient is on TPN, also check serum concentrations of
albumin, glucose, phosphate, calcium, magnesium, transaminases, alkaline
phosphatase, and bilirubin. Optimize volume status preoperatively by
intravenous rehydration.