Tropical sprue
• In some tropical regions, locals and tourists; It is a clinical picture with chronic diarrhea, steatorrhea, weight loss and nutritional disorders.
• Infectious agents are blamed in its etiology.
• Histological changes are similar to gluten enteropathy, but these changes do not improve with a gluten-free diet.
• Tetracycline and folate replacement are given in treatment.
Abetalipoproteinemia
• Enterocytes do not have apoprotein B, so chylomicron cannot be made. As a result, lipids absorbed from the intestines are trapped in enterocytes.
• In intestinal biopsy, epithelial cells are characteristically filled with fat and this finding is diagnostic.
• It is characterized by ataxia, retinitis pigmentosa, low serum cholesterol and triglyceride; Acanthocytes are seen in the peripheral smear.
• In treatment, a diet restricted from triglycerides and fat-soluble vitamins are given.
Whipple's disease
• It is a chronic bacterial infection caused by Tropheryma whipplei.
• It is a chronic multisystemic disease with fever, diarrhea, steatorrhea, weight loss, joint involvement, peripheral lymphadenopathy, cardiac and neurological disorders.
• Multisystemic involvement in a patient with steatorrhea makes Whipple's disease suspicious.
• In the biopsy taken from the small intestine, PAS (+) macrophage infiltration and bacilli are seen.
• Tetracycline or trimethoprim-sulfamethoxazole is used in the treatment.
Excessive Bacterial Growth
• Intestinal flora bacteria generally settle in the distal small intestines and colon.
• Concentration of bacteria in the proximal small intestine for anatomical or functional reasons is called bacterial overgrowth.
• Blind loop syndromes, hypoacidity or achlorhydria, decreased intestinal motility, hypogammaglobulinemia, gastrocolic or jejunocolic fistula may cause this condition.
• Excessive bacterial growth is the most common cause of malabsorption in the elderly.
• These bacteria deconjugate bile acids and impair fat absorption,
cause malabsorption, diarrhea and steatorrhea.
• In addition, bacteria use vitamin B12 and produce folate compounds. Therefore, serum vitamin B12 level decreases, folate level may be found to be normal or high.
• 14C-Xylose breathing test or Schilling test can be used for diagnosis.
• The gold standard test in diagnosis is jejunal aspirate material culture.
• In treatment, antibiotics such as rifaxamine (first choice), neomycin, metronidazole are given.
Lymphangiectasia
• Developed as a result of congenital (primary) or secondary dilatation of intestinal lymphatics and leakage of lymph fluid into the intestinal lumen;
Protein loss, hypoproteinemia, edema (the most important clinical finding)
It is characterized by hypocholesterolemia, lymphopenia, hypocalcemia.
• Diagnosis is made by observing excessively dilated lymphatic channels in biopsy.
• Appropriate diet and replacement are given in treatment. Octreotide may be helpful.
Disaccharidase deficiency
• Disaccharides are absorbed into monosaccharides by disaccharides on the brush border.
• In the absence of these enzymes, disaccharides that cannot be absorbed create an osmotic load in the intestines and are broken down by bacteria, causing excessive gas formation.
• The most common disaccharidase deficiency in adults is lactase deficiency. Abdominal pain, gas and diarrhea are typical after intake of milk and dairy products.
• The H2 breathing test is used for diagnosis.
Pancreatic insufficiency
• The most common cause is chronic pancreatitis due to alcoholism.
• The most important finding is steatorrhea. Qualitative and quantitative fat malabsorption tests are impaired, D-Xylose test and serum carotene level are usually normal.
• Low elastase in stool is helpful in diagnosis.
• Bentiromide test and secretin test are very valuable in diagnosis.
• Pancreatic enzyme extracts are used in the treatment.
Protein-losing enteropathies
• It is characterized by a decrease in serum albumin and globulin and peripheral edema when there is no liver-kidney pathology.
• It is divided into 3 subtypes according to its pathophysiology:
Mucosal erosion: Ulcerative colitis, GIS cancers, peptic ulcer etc.
Increased mucosal permeability (no mucosal erosion): Celiac disease, Menetrier's disease etc.
Lymphatic obstruction: Lymphangiectasia, cardiac causes etc.
• Low globulin along with albumin is useful in differentiating it from other diseases such as cirrhosis and nephrotic syndrome, which are characterized by hypoalbuminemia.
• For diagnosis, stool alpha-1 antitrypsin clearance is evaluated.