1, Routine laboratory tests Blood routine and biochemical tests can help understand whether there is anemia, leukocytosis, diabetes, as well as electrolyte and acid-base balance. Fresh fecal examination is the most important step in diagnosing the cause of acute and chronic diarrhea, and can detect bleeding, pus cells, protozoa, worm eggs, lipomas, undigested food, etc. The occult blood test can detect invisible bleeding. Fecal culture can detect pathogenic microorganisms. Sometimes, to distinguish between secretory diarrhea and hypertonic diarrhea, it is necessary to check fecal electrolytes and osmotic pressure.
2, Small intestine absorption function test
(1)Fecal fat determination: The simplest qualitative examination method is to observe fat droplets under a microscope after staining the fecal smear with Sudan III, and the fecal fat content is15More than % are usually positive. The fat balance test is a chemical method to determine the daily fecal fat content, with the most accurate results.131Jod-Triglycerides and131Jod-Oleic acid absorption test is relatively simple but less accurate than the balance test. When the amount of fecal fat exceeds the normal level, it indicates malabsorption of fat, which can be caused by changes in the intestinal mucosa, excessive bacteria in the intestines, or insufficient pancreatic exocrine secretion.
(2)D-Xylose absorption test: A positive result reflects malabsorption caused by jejunitis or excessive bacteria in the small intestine. In diseases with insufficient pancreatic exocrine secretion or affecting only the ileum, the xylose test is normal.
(3)Vitamin B12Absorption test (Schilling test) In cases of malfunction of the ileum or excessive resection, excessive bacteria in the intestines, or pernicious anemia, vitamin B12Die Urinausscheidung liegt unter dem Normalwert.
(4)Pancreatic function test: Abnormal function indicates that malabsorption of the small intestine is caused by pancreatic disease.
(5)Breath test: ①14C-Glycin breath test: When there is malfunction of the ileum or excessive resection of the small intestine, as well as excessive bacteria in the small intestine, the CO2 exhaled by the lungs2und CO2, das mit den Fäkalien ausgeschieden wird2Signifikant erhöht.②Hydrogen breath test: It is valuable for diagnosing lactose or other disaccharide malabsorption, excessive bacteria in the small intestine, or rapid small intestine transit.