Malnutrition in Gastrointestinal Disorders: Detection and Nutritional Assessment.

All patients with significant gastrointestinal disease should be clinically assessed for protein calorie malnutrition by using the Subjective Global Assessment. Blood tests for anemia, electrolytes, calcium, phosphorus, magnesium, ferritin, vitamin B12, and folate should be considered for assessment of major micronutrients. Where malabsorption or inflammatory bowel disease is diagnosed, bone mineral density using dual beam x-ray absorptiometry, 25-OH vitamin D levels, and measurement of other vitamins and trace elements should be considered. In addition, in at-risk patients, vitamin and trace element clinical deficiency syndromes should be considered during patient assessment.