GI Flashcards
Constipation
Small, infrequent, or difficult BM
Fewer than 3 BMs/week
Constipation causes
Diet (low in fiber) Lack of exercise Slowed peristalsis Pathologic conditions causing constipation Obstruction or diverticulitis
Impaction
Unrelieved constipation may lead to obstruction
Firm, immovable mass of stool obstructing lower GI tract
Impaction symptoms
May have continuous oozing or diarrhea Loss of appetite N/V Abdominal distention Cramping and pain
Diarrhea
Increase in frequency and fluidity of bowel movements
Acute diarrhea causes
Infection, emotional stress, some medications
Acute diarrhea
Make sure liquid stool around an impaction is not misdiagnosed as acute diarrhea
Chronic diarrhea
Lasting more than 4 weeks
Chronic diarrhea causes
Chronic GI infection
Alterations in motility or integrity of GI tract
Malabsorption
Endocrine disorders
Episodic diarrhea
Food allergy or irritant (i.e. caffeine, enteral feeding)
Osmotic diarrhea
Caused by increasing amounts of osmotically active solutes
Typically related to magnesium sulfate or Epsom salt
Ingestion of magnesium sulfate causes sodium/water to enter colon
Common with tube feeding
Osmotic diarrhea
Magnesium sulfate
Secretory diarrhea
Caused by bacteria or toxin
Toxin can increase reabsorption of water in colon
Bacteria typically involved: Vibrio cholerae & Staphylococcus aureus
Exudative diarrhea
Active sites of inflammation in the bowel lumen that results in exudation of mucus, blood, and proteins which pulls water into the colon
Usually related to Cronhs or ulcerative colitis
Motility diarrhea
Related to decreased absorption in the small intestine/large amounts of fluid delivered to the colon
Example: dumping syndrome after gastrectomy or IBS
Problems caused by diarrhea
Skin breakdown
Fluid/Electrolyte imbalance
Nutritional concerns
More concerned for these complications in children and older adults
bismuth subsalicylate (Pepto-Bismol) class
Adsorbent anti-diarrheal
bismuth subsalicylate (Pepto-Bismol)
A form of aspirin
Activated charcoal
bismuth subsalicylate (Pepto-Bismol) MOA
Coats the walls of the GI tract and bind the causative agent for elimination through stool
bismuth subsalicylate (Pepto-Bismol) SE
Increased bleeding time (with warfarin)
Constipation
Dark stools and darkening of tongue
loperamide (Imodium), diphenoxylate with atropine (Lomotil) class
Antimotility anti-diarrheal
loperamide (Imodium) MOA
Inhibits peristalsis by reducing smooth muscle contractions of the GI tract
Inhibits intestinal secretion, decreasing stool water content
No anticholinergic effects
diphenoxylate with atropine (Lomotil) MOA
Inhibits GI motility
When taken in large dosages, atropine causes extreme anticholinergic effects (drying effects/reduce gastric secretions)
loperamide (Imodium), diphenoxylate with atropine (Lomotil)
Antimotility
Used alone or in combination with adsorbents and opiates
loperamide (Imodium), diphenoxylate with atropine (Lomotil) SEs (related to anticholinergic effects from atropine; wouldn’t have these with loperamide alone)
Urinary retention, headache, dizziness, anxiety, drowsiness, bradycardia, hypotension, dry skin, flushing
Probiotics
Obtained from bacterial cultures, most commonly lactobacillus organisms (Bacid, Culturelle) which make up normal flora
Lactobacillus organisms (Bacid, Culturelle)
These bacteria make up the majority of normal flora of gut; bacteria often destroyed by abx so probiotics good for patients with diarrhea from abx
Saccharomyces boulardii (Florastor)
Probiotic used to treat C-Diff
Probiotics MOA
Restore normal flora
Laxatives
For treatment of constipation One of the most misused medication; can lead to dependence Treatment is Individualized: Age Severity Contributing factors
Laxatives groups
Bulk-forming Emollient Hyperosmotic Saline Stimulant
psyllium (Metamucil)
Bulk-forming laxative
psyllium (Metamucil) MOA
Acts similar to dietary fiber
Absorbs water into the intestine, increasing bulk
Distends bowel to initiate reflex bowel activity and bowel movement
psyllium (Metamucil)
Safe for long-term use
psyllium (Metamucil) SEs
Impaction above strictures
Fluid/electrolyte imbalance
Gas formation
Esophageal blockage (must take bulk-forming with increased water to avoid esophageal obstruction)
psyllium (Metamucil) systemic
No systemic effects; actions limited to GI
psyllium (Metamucil)/bulk-forming laxatives contraindication
Contraindicated in patients with intestinal obstruction or fecal impaction
docusate sodium (Colace)
Emollient laxative (stool softener)
docusate sodium (Colace) MOA
Lubricates fecal material and intestinal walls, promotes fat absorption into fecal mass which softens stool, increases secretion of water by the intestine
Lubrication of fecal material and promoting fat absorption into fecal matter
docusate sodium (Colace) indications
Prevent opioid-induced constipation; commonly used post-op
docusate sodium (Colace)
Given PO
mineral oil
Emollient laxative
mineral oil MOA
lubricate intestines, prevents water from moving out of intestines
mineral oil indication
fecal impactions
mineral oil route
PO
PR (per rectum)
Enema
docusate sodium (Colace), mineral oil
Emollient laxative
docusate sodium (Colace), mineral oil SEs
Skin rashes
Decreased absorption of vitamins
glycerin, lactulose and polyethylene glycol
Hyperosmotic laxatives
glycerin, lactulose and polyethylene glycol MOA
INCREASES WATER CONTENT IN FECES
Promotes distention, peristalsis, and evacuation
glycerin
Mild, commonly used in children, typically given as a suppository
lactulose
Digested in the large intestine creating a hyperosmotic environment
Draws water into the colon
Helps reduce blood ammonia levels—commonly used in liver disease/hepatic encephalopathy
polyethylene glycol
Commonly given before surgical/diagnostic bowel procedures (i.e., colonoscopy)
Very potent
Usually reconstituted in fluids
glycerin, lactulose and polyethylene glycol/ hyperosmotic laxative indication
Evacuate bowels before diagnostics and surgical procedures
glycerin, lactulose and polyethylene glycol
Hyperosmotic laxatives
glycerin, lactulose and polyethylene glycol/ hyperosmotic laxatives SEs
Abdominal bloating
Rectal irritation
Electrolyte imbalances
Magnesium salts, sodium salts
Saline laxatives
Magnesium Salts (saline laxative)
magnesium citrate (Citroma) magnesium hydroxide (Phillips Milk of Magnesia) magnesium sulfate (epsom salts)
Magnesium Salts (saline laxative)
Available OTC
Can lead to hypermagnesemia so use cautiously in renal patients
Sodium Salts (saline laxative)
Fleet enema
Magnesium salts, sodium salts (saline laxatives) MOA
Increase osmotic pressure and draw water into colon; as water moves into the bowel, it increases the pressure in the bowel and increases peristalsis
Magnesium salts, sodium salts (saline laxatives) SEs
Magnesium toxicity
Electrolyte imbalance
Cramping
Diarrhea
bisacodyl (Ducolax), senna (Senokot)
Stimulant laxatives
bisacodyl (Ducolax), senna (Senokot)/stimulant laxatives MOA
Induce intestinal peristalsis
bisacodyl (Ducolax) route
PO and PR
senna (Senokot) route
PO
bisacodyl (Ducolax), senna (Senokot): stimulant laxatives
Class of laxatives MOST LIKELY to cause dependence
bisacodyl (Ducolax), senna (Senokot)/ stimulant laxatives indications
Constipation or whole bowel evacuation; works on the entire GI tract
bisacodyl (Ducolax), senna (Senokot): stimulant laxatives SEs
Nutrient malabsorption, gastric irritation, electrolyte imbalance
Anti-diarrheals groups
Adsorbents
Antimotility (anticholinergics and opiates; opiates not commonly used due to CNS depression)
Probiotics
Antimotility anti-diarrheals
Anticholinergics and opiates; opiates not commonly used due to CNS depression
Anti-diarrheals route
All PO
Magnesium hydroxide contraindication
Kidney dysfunction due to magnesium buildup
Bulk forming laxative
Drug of choice for chronic constipation
