Page 35 - To keep a balance in disease specific intestinal insufficiency. Diagnostics and practical nutritional aspects - Nicolette Wierdsma

Diagnostic tests for malabsorption and maldigestion
Dysmotility may comprise both increased (hypermotility) as well as decreased
motility (hypomotility) disorders. In case of hypermotility, an accelerated gastro-intestinal transit time occurs, leading to insufficient contact time
or uncoordinated or inadequate release of digestive enzymes. In case of hypomotility, intestinal stasis may result with subsequent bacterial overgrowth.
Chronic intermittent, intestinal, pseudo-obstruction (CIIP), a relatively frequently
missed diagnosis, is characterized by dysmotility with a mixed and alternately 3 clinically apparent motility disorder, but may be chronic and ongoing. Motility
disorders are commonly subdivided in the intestinal segments in which these occur: esophagus, stomach, small intestine and colon.
Malassimilation may be a consequence of (a combination of) maldigestion, malabsorption or dysmotility. Reduction of the functional small intestinal area, e.g. following extensive or repetitive intestinal surgery, or radiotherapy in cancer patients, or insufficient mesenterial blood flow in multiple organ dysfunction syndrome patients, results in diminished functional enterocyte mass. Dysfunction of the intestinal barrier function, usually measured by (increased) intestinal permeability, can be caused by use of antibiotics, toxins, a poor diet, parasites or other infections. A‘leaky gut syndrome’may occur as a consequence. GI disorders characterized by malfunction of normal GI activities, but without explaining structural abnormalities, are so-called ‘functional’ GI disorders. There are rarely any tests that can detect the presence of these disorders. Irritable bowel syndrome is considered to be the commonest functional GI disorder.
Assessment of intestinal (patho)physiology
No gold standard, unambiguous and validated test for the various underlying and contributing aspects of intestinal function is available. Yet, several specified or partial intestinal function tests are available, e.g. for detecting or assessing maldigestion, malabsorption, dysmotility, malassimilation (nutrients and intestinal mass) and (changed) intestinal barrier characteristics. Not every test is suitable for each situation and several are only available in research but cannot be used in clinical practice.
Assessment of (mal)digestion
A limited number of tests are available to assess (mal)digestion, like Lundh test and disaccharide breath tests.
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