Term
Match mL to areas of activity:
1. 1400mL, 2. 7000mL, 3. 100mL
a. small intestine absorption, b. large intestine absorption, c. excretion |
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Definition
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Term
Which of the following are mechs of diarrhea?
a. too much input, b. lack of absorption, c. too much absorption, d. excess secretion, e. not enough secretion, f. Increased bowel motility, g. increased bowel surf area, h. dec bowel SA, i. inflammation, j. osmotic diarrhea |
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Definition
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Term
| What's the content of secretory diarrhea |
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Definition
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Term
Does fasting help secretory diarrhea go away?
Do you see WBCs/RBCs in secretory diarrhea? |
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Definition
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Term
| T/F: Vibrio cholerae is an invasive bacteria that destroys Na/Cl channels. |
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Definition
| False, it's not invasive, it uses toxins to decrease the Na/Cl reabsorption channel and increases the transport of the Cl- EXPORT channel via the toxin increasing the cAMP pathways. |
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Term
| Key stool lab findings in secretory diarrhea? |
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Definition
High: Na, Cl, HCO3-, and overall volume
Low: K+, anions, Mg++, volume |
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Term
| Electrolyte abnormalities in sec diarrhea px? |
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Definition
Hypokalemia (loss of K in stools)
Acidosis (loss of bicarbonate in stools)
Hyponatremia (loss of Na in stools and oral intake of free water) |
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Term
| Name the bacterial, inflamm mediator, and hormonal causes of intestinal secretion (stimulating NaCl secretion) |
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Definition
Bacterial toxins
Cholera, E. coli, Shigella (early on watery diarrhea), etc.
Inflammatory mediators
prostaglandins
Circulating hormones
Gastrin (Z-E syndrome), Vasoactive intestinal polypeptide (VIP) |
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Term
| What other things contribute to secretion? |
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Definition
Malabsorbed compounds that reach the colon and stimulate secretion
Bile acids
Fatty acids
Laxatives (“natural” from plants) that stimulate secretion
Ricinoleic acid
Senokot
Lack of mature villus/surface absorptive cells reducing absorption
viral gastroenteritis/celiac sprue |
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Term
| Why is it that sorbitol, lactose, Mg salts such as MOM/Mg citrate => diarrhea? |
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Definition
| they can't be absorbed and must be diluted to isotonicity |
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Term
| Review the pathophysiology of sorbitol and osmotic diarrhea |
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Definition
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Term
| osmotic diarrhea from sorbitol is due to three factors. what are they? |
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Definition
Amount of ingested material containing non-absorbed solute.
Volume of extra water needed to dilute the ingested material to isotonicity
Volume of water accompanying the Na, Cl and other ions that equilibrate across the gut epithelia. |
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Term
Which of the following is true in osmotic diarrhea?
1. large volume of stool
2. gets worse with oral intake
3. watery soft stoo
4. increased flatus
5. presence of WBCs/RBCs |
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Definition
1. F
2. F
3. T
4. T (due to carb malabsorption)
5. F |
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Term
| Name some other causes of osmotic diarrhea besides sorbitol |
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Definition
Mg salts (antacids: maalox, mylanta...laxatives: MOM), Sugars (lactuolse, sorbitol, mannitol, fructose, lactose)
Malabsorption of specific carbohydrates
Disaccharidase deficiency
Generalized malabsorption of nutrients |
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Term
| How do the osmotic gap between malabsorption of carbs compare with that of osmotic diarrhea due to Mg salt? |
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Definition
| Osmotic diarrhea has 2X greater fecal osmotic gap (200 vs. 100...vs. 30 normally), due to the fact that Na/K are actually decreased in the feces and there is a greater contribution from increased Cl- and other anions such as SO4-2, PO4-2, and Mg). |
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Term
| Diarrhea due to increased bowel motility can be triggered by what? |
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Definition
Reduced contact time between luminal
contents and bowel mucosa.
Anxiety,
Hyperthyroidism,
Irritable bowel syndrome
Postvagotomy diarrhea (dumping syndrome)
Bowel infection (viral gastroenteritis) |
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Term
Which of the following are features of increased bowel motility?
1. Moderate diarrhea - usually watery
2. Often occurs after meals - accentuated gastro-colic reflex
3. WBC, RBC in stool
4. Recently eaten food visable in stools
5. Quiet bowel sounds often apparent
6. Easily diagnosed with a simple stool test |
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Definition
All true except
3. False: No WBC, RBC in stool
5. False: Louder bowel sounds often apparent
6. No diagnostic tests- often must rule-out secretory/osmotic/inflammatory causes |
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Term
| Consequences of increased bowel motility |
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Definition
Malabsorption and weightloss
Nutrients (if small bowel is involved)
Diarrhea and urgency
Increased bowel sounds (if severe)
Crampy abdominal pain (if severe) |
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Term
| What kind of diarrhea does loss of bowel surface area mimic? What is it caused by? |
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Definition
Increased bowel motility
Caused by: Causes include surgical resection, mucosal disease, fistulas |
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Term
| How does a viral infection => malabsorption? |
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Definition
Viral infection temporarily destroys mature villus enterocytes
and can cause some malabsorption/secretion |
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Term
| 4 Mechanisms of diarrhea after inflammatory process |
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Definition
1. stimulated sec/inhibited absorption
2. stim of enteric nerves => propulsive contractions/stimulated secretion
3. mucosal destruction/inc permeability
4. nutrient maldigestion/malabsorption |
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Term
A 15 yr old comes in with a fever, small to moderate vol of diarrhea and WBCs/RBCs in his stool, reporting heavy cramps and urgency. What kind of diarrhea does he have?
1. Secretory due to vibrio cholerae
2. Rapid motility
3. Inflammatory diarrhea
4. Malabsorption diarrhea |
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Definition
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Term
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Definition
Infectious diarrhea (viral, bacterial, parasitic)
Idiopathic inflammatory bowel disease (Crohn’s disease, Ulcerative colitis
microscopic colitis)
Response to ischemia/injury |
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Term
| What do Crohn's and ulcerative colitis both do to the bowels => diarrhea? |
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Definition
| inflammation causing damaged mucosa => reduced area for absorption |
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Term
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Definition
| infections inflammatory bowel disease microscopic colitis lymphoma/ischemia |
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Term
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Definition
| symptomatic therapy may be critical to patient survival and the only available approach |
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Term
| Why does ORT work for cholera px? |
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Definition
| Chol toxins do not affect the Na/Glucose cotransporters!!! So this utilizes them! |
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Term
| What's the role of anti-motility agents (opiates?) |
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Definition
Increase capacitance of gut and thus time for reabsorption
Useful in many types of diarrhea if specific therapy is not available or adequate
Often need to use large doses and/or potent drugs and administer on a regular (rather than PRN) basis.
Do not use in acute bloody diarrhea (infectious or inflammatory) |
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