What is the difference between osmotic and secretory diarrhea?
Osmotic diarrhea occurs when you eat substances that can’t be absorbed. Secretory diarrhea occurs when your body secretes electrolytes into your intestine. This causes water to build up.
What does stool osmotic gap tell you?
Determines if chronic diarrhea is osmotic or secretory in nature. Use with persistent (>4 weeks) watery diarrhea (>3 episodes/day) to guide diagnosis and treatment. Useful to determine whether chronic watery diarrhea is from osmotic or secretory causes.
How does osmosis affect diarrhea?
Osmotic diarrhea results from the presence of osmotically active, poorly absorbed solutes in the bowel lumen that inhibit normal water and electrolyte absorption. Certain laxatives such as lactulose and citrate of magnesia or maldigestion of certain food substances such as milk are common causes of osmotic diarrhea.
What causes secretory diarrhea?
Secretory diarrhea can result from bacterial toxins, reduced absorptive surface area caused by disease or resection, luminal secretagogues (such as bile acids or laxatives), circulating secretagogues (such as various hormones, drugs, and poisons), and medical problems that compromise regulation of intestinal function.
What is osmotic gap?
From Wikipedia, the free encyclopedia. Stool osmotic gap is a measurement of the difference in solute types between serum and feces, used to distinguish among different causes of diarrhea. Feces is normally in osmotic equilibrium with blood serum, which the human body maintains between 290–300 mOsm/kg.
How do you calculate osmotic gap?
Calculation. The osmol gap is typically calculated as: OG = measured serum osmolality − calculated osmolality. A normal osmol gap is < 10 mOsm/kg .
Why does osmotic diarrhea have high osmotic gap?
The reason for this is that secreted sodium and potassium ions make up a greater percentage of the stool osmolality in secretory diarrhea, whereas in osmotic diarrhea, other molecules such as unabsorbed carbohydrates are more significant contributors to stool osmolality.
How do you test for osmotic diarrhea?
These tests may include:
- Complete blood count, or CBC, and differential.
- Thyroid function.
- Serum electrolytes.
- Total protein.
- Stool occult blood.
- Stool test to look for the active ingredients in laxatives.
- Sigmoidoscopy or colonoscopy.
Is secretory diarrhea watery?
Watery diarrhea may be subdivided into osmotic, secretory, and functional types. Watery diarrhea includes irritable bowel syndrome, which is the most common cause of functional diarrhea. Another example of watery diarrhea is microscopic colitis, which is a secretory diarrhea affecting older persons.
Why is secretory diarrhea isotonic?
The A (active) subunit acts as a ribosyl transferase and covalently links ADP ribose to Gsα; it thereby upregulates adenylate cyclase activity. The resulting persistent increase in intracellular cAMP causes excessive secretion of isotonic fluid into the intestine.
How do you treat secretory diarrhea?
The current standard therapy for SED is oral rehydration therapy (ORT) which involves fluid replacement using a mixture of water, salts, and glucose in specific proportions. ORT is useful and may reduce diarrhea mortality by up to 93% in children under the age of 5.
What is the osmotic gap in osmotic diarrhea?
Stool osmotic gap is a measurement of the difference in solute types between serum and feces, used to distinguish among different causes of diarrhea. Feces is normally in osmotic equilibrium with blood serum, which the human body maintains between 290–300 mOsm/kg.
How to distinguish between osmotic and secretory diarrhoea?
Differentiation of osmotic and secretory diarrhoea by stool carbohydrate and osmolar gap measurements Clinical features and laboratory tests that determine carbohydrate in faeces were evaluated to determine which was best able to distinguish between osmotic and secretory diarrhoea in infants and children.
What is Stool osmotic gap in microbiology?
Stool osmotic gap. Stool osmotic gap is an measurement of the difference in solute types between serum and feces, used to distinguish among different causes of diarrhea.
What causes low osmotic gap in diarrhea?
Low osmotic gap (<50 mOsm/kg) causes of secretory diarrhea include toxin-mediated causes (cholera, enterotoxigenic strains of E. coli) and secretagogues such as vasoactive intestinal peptide (from a VIPoma, for example).
How is the faecal osmolar gap calculated in acute watery diarrhoea?
For this purpose 80 boys aged 3 to 24 months, with acute watery diarrhoea, were studied prospectively. The faecal osmolar gap (FOG) was calculated as: serum osmolarity − [2 × (faecal sodium + potassium concentration)].