Page 37 - To keep a balance in disease specific intestinal insufficiency. Diagnostics and practical nutritional aspects - Nicolette Wierdsma
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Diagnostic tests for malabsorption and maldigestion
20 ppm of hydrogen and/or methane within the first two hours (indicating bacteria in the small intestine) and followed by a much larger peak, indicating the colonic response. Flaws of the test comprise, among others, failed fasting, concurrent smoking, constipation and methane producing fermenting bacteria instead of H2-producers.
Assessment of (mal)absorption 3 Intestinal losses can be quantified by measurement of fecal (unabsorbed)
nutrients. Consecutively, specific fecal tests for fat, protein and energy will be
discussed. For carbohydrates, no appropriate, easily accessible (or feasible) test
is available.
Assessment of fat (mal)absorption
Fecal fat excretion test
Classically, fecal fat content can be measured chemically and quantified by the van de Kamer-method. Collected feces of several days (preferably 3-7), usually in combination with a pretest period of 4-7 days for consumption of a diet saturated with a known, or standardized amount of fat (11). The intestinal absorption capacity of fat can be calculated by extracting fecal fat from ingested fat and expressed as a percentage of ingested fat. The underlying concept of the fecal fat excretion test is that the malabsorption of fat correlates with malabsorption in general (11). It should be realized, however, that fat-malabsorption reflects only to a certain extent the total absorptive capacities of the intestine.
Qualitative fecal fat screening
In a qualitative and semi-quantitative way, fecal fat can be demonstrated with Sudan III staining. By using Sudan III solution, the fat (and fatty acids) actually present in feces, will be colored (orange) after heating. The amount of fat is scored semi-quantitatively, and therefore this method is most commonly used as a rough estimate or screening tool.
Triolein-lipid absorption test
Other tests for detecting fat malabsorption, lipolysis and to assess the efficacy of pancreatic enzyme supplementation are used as well, like breath test with radioactively labeled 14C-triolein.The test seems most stable, with high sensitivity
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