Ch. 15 - Constipation Flashcards
1
Q
Constipation
A
- Common GI complain
- <3 bowel movements/week that are strained and result in difficult passage of hard, dry stools
- Results from slow movement of feces in colon which results in accumulation in descending colon
- Elderly 5x more likely, women 3 x more likely than men
2
Q
Constipation described as… (5)
A
- Straining for bowel movements
- Passing hard, dry stools
- Passing small stools
- Feeling as though bowel movements aren’t complete
- Reduced stool frequency
3
Q
Constipation Pathophysiology
A
- Food normally in stomach and small intestine for 3 hours each
- Ingestible matter absorbed and indigestible into large intestine and stored in sigmoid colon until defecation
- Peristaltic movement mores fecal matter into rectum and causes the desire to poop, relaxation of internal sphincter and tightening of abdominal wall muscles which causes a Valsalva maneuver forces poop down
- Defecation is this voluntarily inhibited or facilitated
- Primary or secondary in causation, primary is defecation disorders or slower-than-normal fecal movements
- Secondary causes: systemic, neurological, or psychological disorders or abnormalities that cause obstructions
- Dietary fiber dissolves or swells in intestinal fluids to increase fecal mass and peristaltic motions
- Diets low in calories, carbs, or fiber can lead to constipation
- Inadequate fluids and dehydration can cause constipation
- Exercise increases muscle tone and promotes bowel motility
- Resisting defecation urges can lead to constipation that may require retraining
- Medications can also cause constipation (Ex: opioids)
4
Q
Constipation Clinical Presentation
A
- Besides constipation, also anorexia, dull HA, lassitude, low back pain, abdominal discomfort, bloating, flatulence, and psychological distress
- Sporadic, temporary constipation okay to self-treat
- Constipation continuing over several weeks or months should be referred to PCP
- Complications can occur like hemorrhoids, fissures, anal bleeding, rectal prolapse, fecal impactations, ulcers, increase BP and cardiac disruptions
5
Q
Constipation Treatment Goals
A
- Relieve constipation and reestablish normal bowel function
- Establish dietary and exercise habits to prevent
- Promote safe and effective use of laxatives
6
Q
Constipation General Treatment
A
- Adjust diet, increase fluid intake, exercise
- Pharmacologics should be used with these interventions together
- Don’t use pharmacologics for more than 7 days, if needed go to PCP
- Anal bleeding or persistent constipation after using laxatives - medical referral
7
Q
Constipation Exclusions
A
- Marked/severe abdominal pain
- Significant distension/cramping
- Marked/unexplained flatulence
- Fever
- N/V
- Sudden bowel habit changes
- Secondary constipation or constipation presenting with symptoms that may indicate secondary causes
8
Q
Constipation Nonpharmocologic
A
- Increase in fruit, vegetable, fiber, and whole grain intake
- 25 g of fiber for women, 38 g of fiber for men daily
- Limit intake of foods with little to no fiber (cheese, meals, processed foods)
- Can also supplement with fiber supplements like inulin, psyllium, and methylcellulose
- Benefits may take 3-5+ days
- Could initially cause erratic bowel habits, flatulence, and abdominal discomfort for 1st few weeks
- Slowly increase fiber intake over 1-2 weeks, also increase fluid intake to 2 L/day
- Encourage regular physical activity
9
Q
Constipation Pharmacologic
A
Ideal laxative:
- Nonirritating and nontoxic
- Only act on descending colon/sigmoid
- Produces normal bowel movements in a few hours and then laxative stops action and normal function occurs
- NO LAXATIVE HAS ALL THESE, choose based on patient need/etiology
10
Q
Bulk-Forming Agents
A
- Methylcellulose, polycarbophil, psyllium
- Swell/dissolve in small and large intestines to form emollient gels that increase peristalsis and fecal passage
- Many dosage forms available
- Onset: 12-24 hours, may be delayed up to 72 hours
- Provides short term relief for patients on low-fiber diets, postpartum women, older adults, patients with colostomies, IBS, or diverticulitis
- Don’t increase dose pass recommended, could cause obstruction
- Avoid in those who have difficulty, swallowing, restricted fluid intake, palliative care patients
- Avoid psyllium if you are allergic to it
- Many inhibit drug absorption by binding to medications
- Calcium polycarbophil decreases absorption of oral tetracyclines and quinolones by calcium chelation
- Separate bulk laxatives by 2 hours to other medications
- Don’t take if you have intestinal ulcers, stenosis, or disabling adhesion
- Potential SE: diarrhea, abdominal discomfort, flatulence, excessive fluid loss, abdominal cramping
- Access calcium intake in hypercalcemia risk patients, sugar content in diabetes, and aspartame intake in those with phenyketonuria
11
Q
Hyperosmotic Agents
A
- Polyethylene glycol 3350 and glycerin
- Contain large, poorly absorbed ions that draw water into colon or rectum via osmosis
- PEG 3350, good for 17 y.o.+, 17 g mixed in 4-8 oz of water
- Onset: 12-72 hours, delay up to 96 hours
- Only 0.2% systemically absorbed, quickly metabolized
- Safe and effective, few SE
- ASE: bloating, abdominal discomfort, cramping, has
- Caution use in diabetics and IBS
- No significant DD interactions
- Glycerin, suppository that works primarily in colon
- Onset: 15-30 minutes
- Safe for occasional use by all age groups
- Overdose: rectal irritation (don’t use enema version due to this) and decrease serum potassium concentrations
- Minimal SE and insignificant DD interactions
12
Q
Emollient Agents
A
- “Stool softeners,” anionic surfactants increase wetting efficiency of intestinal fluid to soften stool
- Primarily used to decrease straining and painful defecation in those with anorectal disorders
- Often combined with stimulant for long-term treatment of opioid-induced constipation
- Docusate onset: 12-72 hours, effective ~48 hours, sometimes medication requires 3-5 days
- Possible SE: diarrhea, mild abdominal cramping (well tolerated), weakness, sweating, muscle cramps, irregular heartbeat
- Don’t use in combination with mineral oil
- Not appreciably absorbed from GI and doesn’t hamper with nutrition absorption
13
Q
Lubricant Agent
A
- Mineral oil only non-Rx lubricant
- Coats fecal matter and prevents colon absorption of fecal
- Available as a liquid for oral or rectal administration
- Onset: 6-8 hours orally, 5-15 minutes rectally
- Prevent straining and painful defecation
- Not as safe as docusate
- Biggest safety concern: lipid pneumonia from aspiration into lungs after oral dose
- Caution use in young children (<6 y.o.), elderly, debilitated or bedridden, swallowing troubles, dysphagia, pregnant women
- Other ASE: anal pruritis, cryptitis, perianal conditions, foreign body reactions from reaching lymph nodes
- May impair fat soluble vitamin and medication absorption, don’t take with food
14
Q
Saline Laxative Agents
A
- Magnesium citrate, magnesium hydroxide, dibasic sodium phosphate, monobasic sodium phosphate, and magnesium sulfate
- Liquid or solid forms for oral or rectal use
- Ions retrained in small and large intestine and draw water in to increase intraluminal pressure and intestinal motility
- Use for occasional constipation relief or acute evacuation before a procedure
15
Q
Magnesium Hydroxide
A
- Magnesium hydroxide - good for occasional constipation in health patients; onset: 30 minutes - 6 hours
- Other preparations generally used for acute catharsis; onset: 30 minutes - 3 hours (oral), or 2-15 minutes (rectally), not recommended for OTC use since there are safer options
- ASE: cramping, N/V, or dehydration (drink with glass of water to decrease this SE)
- Can cause serious electrolyte imbalances after prolonged use or high doses
- Don’t recommend for electrolyte restricted diets
- Increased risk of magnesium toxicity in newborns, elderly, and renally impaired (avoid in these population)
- Magnesium preparations interact with tetracyclines
- Magnesium + Sodium Polystyrene Sulfate: systemic alkosis can occur
