Pathophysiology of failure to thrive in gastrointestinal disorders.

What will be our GI approach to a child with FTT syndrome? Detailed history and physical examination will give us the clue and often the probable diagnosis. Several laboratory tests are helpful in establishing the fact that there is malabsorption. Among them are a complete blood count with smear, quantitative stool fat excretion, serum protein and chemistry screen panel, prothrombin time, and oral tolerance and absorption--i.e., of glucose, iron, vitamin A, and xylose. Specialized procedures may be used to nail down the diagnosis: radiology, biopsy, duodenal intubation, etc. These should never be employed as routine screening tests, however. In outlining a comprehensive and successful therapy, the attending physician will find it helpful to consider the particular pathophysiologic mechanisms of a specific disease. Exact diagnosis makes the therapy both rational and effective.