Term
| Name four ways that laxatives may ease or stimulate defecation. |
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Definition
1.Can soften the stool 2. Increase stool volume 3. Hasten fecal passage through the intestine 4. Facilitate evacuation from the rectum |
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Term
| v What is misuse of laxatives largely the result of? |
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Definition
| Misconceptions about what constitutes normal bowel function |
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Term
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Definition
Production of a soft, formed stool over a period of 1 or more days. |
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Term
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Definition
A prompt, fluid evacuation of the bowel (A laxative effect is leisurely and relatively mild, whereas catharsis is relatively fast and intense.) |
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Term
| v Describe a normal frequency of bowel movement. |
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Definition
| Because of wide individual variation we can’t define a normal frequency for bowel movements. |
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Term
| How does fiber facilitate colonic function? |
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Definition
1. It can absorb water, thereby softening the feces and increasing their mass. 2. It can be digested by colonic bacteria, whose subsequent growth increases fecal mass.(the best source of fiber is bran. Can b obtain from fruit and vegs. 20 – 60g/day = optimize intestinal function). |
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Term
| List six symptoms that a patient may use to define constipation |
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Definition
1-Hard stools, 2- Infrequent stools, 3- Excessive straining, 4-Prolonged effort, 5- A sense of incomplete evacuation, 6- Unsuccessful defecation. |
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Term
v What factor is more significant in determining constipation, frequency or stool consistency?
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Definition
| Stool consistency (degree of hardness) |
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Term
| v What is a common cause of constipation? . |
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Definition
| Poor diet- specifically a diet deficient in fiber and fluid |
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Term
v In addition to adding fiber and fluid to the diet, what other action will help improve bowel function?
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Definition
| Mild exercise, especially after meals |
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Term
| laxatives should not be used in patients with |
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Definition
fecal impaction obstruction of the bowel because increased peristalsis could cause bowel perforation |
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Term
| v List the four major categories of laxatives traditionally used. |
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Definition
(1)Bulk forming laxatives (2) Surfactant laxatives (3) Stimulant laxatives (4) Osmotic laxatives. |
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Term
| v Which group of laxatives is most frequently abused? |
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Definition
Group 1, Rapid acting (2-6 hrs)? Group 2, Intermediate acting (6-12 hrs)? or Most abused Group 3, Slow acting (1-3 days)? |
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Term
| What do bulk-forming laxatives consist of?i.e methylcellulose, psyllium. |
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Definition
Natural and semisynthetic polysaccharides and cellulses derived from grains and other plant material |
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Term
| v How soon can one expect buck-forming laxatives to have a clinical response? . |
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Definition
| They produce a soft, formed stool 1 to 3 days after onset of treatment |
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Term
What is the primary mechanism of action of bulk-forming laxatives? Why is transit through the intestine hastened?
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Definition
- Following ingestion, it swell in water to form a viscous solution or gel, thereby softening the fecal mass and increasing its bulk.
- transit through the intestine is hastened because swelling of the fecal mass stretches the intestinal wall, thereby stimulating peristalsis.
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Term
| v What should be provided with bulk-forming laxatives when administered? |
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Definition
| A full glass of water or juice. |
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Term
| v What is a common brand name for psyllium ? (p. 907, table 77-4) |
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Definition
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Term
| v How soon can one expect surfactant laxatives to have a clinical response? |
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Definition
| Several days after the onset of treatment |
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Term
| v What is the main mechanism of action of surfactant laxatives? |
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Definition
| Alter stool consistency by lowering surface tension, which facilitates penetration of water into feces. May act on intestinal wall to 1- inhibit fluid absorption and 2- stimulate secretion of water and electrolytes into intestinal lumen. (resemble stimulant laxatives) |
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Term
What is the brand name for docusate sodium? |
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Definition
Colace, Ex-Lax Stool softener, Modane Soft, Phillips Liqui-Gels, Dulcolax Stool Softener Liquid Gels, others. |
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Term
| v What should be provided with surfactant laxatives when administered? |
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Definition
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Term
| Describe the two mechanisms of action for stimulant laxatives. |
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Definition
(1)They stimulate intestinal motility- hence their name (2) They increase the amount of water and electrolytes within the intestinal lumen.
(by incr. secretion of water and ions into intestine, and reducing water and electrolyte absorption) |
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Term
| How soon can one expect stimulant laxatives to have a clinical response? |
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Definition
| They act on colon, producing a semifluid stool within 6 to 12 hours |
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Term
| List three common brand names for bisacodyl |
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Definition
| *Correctol, *Dulcolax, Fleet Laxative,* Feen-a-mint. |
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Term
| v How rapid is the response to bisacodyl suppositories? |
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Definition
Rapidly (in 15 to 60 minutes).
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Term
| v What is the mechanism of action of laxative salts? ). |
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Definition
| Poorly absorbed salts whose osmotic action draws water into the intestinal lumen.(accumulation of water causes the fecal mass to soften and swell, thereby stretching the intestinal wall, which stimulates peristalsis |
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Term
| v When laxative salts are administered in low doses what is the expected clinical response? In high doses? |
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Definition
| Low= Produce a soft or semifluid stool in 6 to 12 hours.High= Act rapidly (in 2 to 6 hours) to cause a fluid evacuation of the bowel. (used in prep for diagnostic or surgical procedures). |
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Term
| v Name a common brand of the laxative salt, magnesium hydroxide. (p. 908 and 907, table 77-4) |
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Definition
| Dulcolax Milk of Magnesia. |
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Term
| v Briefly explain how laxatives can perpetuate their own use. |
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Definition
| Strong laxatives can purge the entire bowel. When such overemptying occurs, spontaneous evacuation is impossible until bowel content has been replenished, which can take 2 to 5 days. During this time, the laxative user, having experienced no movement of the bowel, often becomes convinced that constipation has returned. In response, he or she takes yet another dose, which purges the bowel once more, and thereby sets the stage for a repeating cycle of laxative use and purging. |
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Term
| v Identify four consequences of chronic exposure to laxatives. |
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Definition
(1) Can diminish defecatory reflexes, leading to further reliance on laxatives. Laxative abuse = more serious pathological changes including (2) Electrolyte imbalance, (3) Dehydration, and (4) Colitis. |
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Term
| v Summarize steps a person may take to break the laxative habit. |
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Definition
| 1st abrupt cessation of laxative use.(after withdrawal, bm absent for several days, inform pt of this) Correct misconceptions pt has regarding bowel function: pt should be taught that once a day bm may not be normal for him or her and that stool quality is more important than frequency or quantity. Instruction on bowel training (heeding defecatory reflex, establishing a consistent time for bms) should be provided. Increased consumption of fiber (bran, fruits, vegs) and fluid should be stressed. Pt should be encouraged to exercise daily, especially after meals. Finally pt. should be advised that, if a laxative must be used, it should be used briefly and in the smallest effective dose. Agents that produce catharsis must be avoided |
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