Malabsorpton Flashcards
Define malabsorption
Defective mucosal absorption
What are common causes of malabsorption
Coeliac Chron's Post Infectious Biliary obstruction Cirrhosis
What are uncommon causes of malabsorption
Pancreatic cancer Parasites Bacterial Overgrowth Drugs Short Bowel
Digestive causes of protein malabsorption
Partial or total gastrectomy
Exocrine pancreatic insufficiency
Trypsinogen deficiency
Congenital deficiency of enterokinase
Absorptive causes of protein malabsorption
Coeliac disease Methionine malabsorption Short bowel Jejunoilial bypas Hartsnup disease (defects in neutral AA transporter) Cystinuria I-III Occulucerebral syndrome of Lowe
Digestive causes of fat malabsorption
Less time to mix- resection, neuropathy, amyloidosis
Decreased micelle formation- biliary obstruction, SIBO, CCK deficiency
Decreased lipolysis- chronic pancreatitis, cystic fibrosis, lipase deficiency
Absorptive causes of fat malabsorption
Decreased chylomicron formation and or mucosal absorption
Post absorptive causes of fat malabsorption
Defective lymphatic transprt- lymphoma, whipples
Digestive causes of carb malabsorption
Severe pancreatic insufficiency
Absorptive causes of carb malabsorption
Primary or acquired lactase deficiency
- post infective
- celiac
- chrons
- trehalase deficiency
Cause of VB12 deficiency
Atrophic gastritis
Intrinsic factor deficiency- pernicious anaemia
Pancreatic insufficiency- zolinger ellis- reduced release of B12 from R binding protein
Helminth infections/SIBO
Ileal/crhon’s disease/resection
Cause of folic acid deficiency
Disease affecting proximal/small bowel
Celiac disease
Whipple
tropical sprue
Alcoholism
Calcium deficiency
Renal disease, genetic, Celiac, bile acid deficiency
Magnesium deficiency
Loss of mucosal surface
Iron deficiency
Reduced mucosal surface area, GI bleed
Zinc deficiency
Acrodermatitis enterohepathica
Copper deficiency
Menkes disease (kinky hair disease
Describe the cause of Celiac
Intestinal antigen presenting cells in people expressing HLA-DQ2 or HLA-DQ8 bind with dietary gluten peptides in their antigen-binding grooves activate specific mucosal T lymphocytes cytokines which cause mucosal damage
Symptoms of Celiac
Spectrum: asymptomatic to nutritional deficiencies weight loss, diarrhoea, excess flatus, and abdominal discomfort
Diagnosis of Celiac
IgA anti-tissue transgulatminase test (tTGA)
Biopsy is confirmative
Cause of lactose malabsorption
Deficiency of lactase
lactose malabsorption presenting complaint
Induction of diarrhoea, abdominal discomfort and flatulence following ingestion of dairy products
Diagnosis of lactose malabsorption
Clinical, confirmed by hydrogen breath test
Cause of tropical sprue
Colonisation of investing by an infectious agent or alterations to intestinal bacterial flora induces by exposure to another environmental agent
Clinical findings in tropical sprue
Diarrhoea, steatorrhoea, weight loss, nausea, anorexia, anaemia
Diagnosis and treatment of tropical sprue
Biopsy
Tetracycline and folic acid
Causes of whipple’s disease
Torpheryma whipplei. Multi system involvement, increase in the frequency of HLA-B27
Clinical findings in whipples disease
Weight loss, steatorrhoea, abdominal distension, arthritis, fever, nutritional deficiency symptoms
Diagnosis of whipple’s disease
Demostration of T.whipplei in involved tissues by microscopc=y
Treatment of T.whipplei
Antimicrobial
Causes of parasitic infections
Giardia lamblia
Risk factors of giardiasis
Travel to areas where the water supply ma be contaminated, swimming in ponds
Clinical findings of giardiasis
Diarrhoea, flatulence, abdo cramps, epigastric pain, nausea,
1/3rd vomit
steatorrhea, weight loss
Testing for parasitic infections
Stool examination for ova and parasites, three separate stools is ideal
Treatment of parasitic infections
Metronidazole- 1 week
Symptoms of SIBO
Diarrhoea, steattorhea, microcytic anaemia
Causes of SIBO
E.coli, bacteroides
Diverticula, fistulas, strictures relating to chron’s disease
Bypass surgeries functional stasis
Lab testing of SIBO
Low cobalamin and high folate
Aerobic/ anaerbic colonic type bacteria in jejunal aspirate obtained by intubation. Established by schillings test
treatment of SIBO
Surgical correction of anatomical blind loop
tetracyclines 2-3 week
