Mosby items and derived items © 2005, 2002 by Mosby, Inc.

. * Abnormally infrequent and difficult passage of feces through the lower GI tract * Symptom, not a disease * Disorder of movement through the colon and/or rectum * Can be caused by a variety of diseases or drugs

* Constipation is generally defined as infrequent and/or unsatisfactory defecation fewer than 3 times per week. * Patients may define constipation as passing hard stools or straining, incomplete or painful defecation.

Epidemiology  2-27% of the population has constipation  Constipation affects twice as many women as men  Constipation is more prevalent in non-White persons than in White persons (non- White:White ratio range )

Causes of constipation Diet Lack of exercise Age Irregular bowel habits Drug induced Disease States/Conditions Spasam of sigmoid colon Dysfunction of myenteric plexus

I’m constipated, now what? Two approaches to consider: Non-drug Approach Drug Approach

No evidence that increased exercise is beneficial in severe constipation Aim for 25-30g fibre/day Unless dehydrated, increasing fluid does not relieve chronic constipation and may increase the risk of fluid overload eg heart or renal failure

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * Bulk forming * Emollient * Hyperosmotic * Saline * Stimulant

Mosby items and derived items © 2005, 2002 by Mosby, Inc. 1. Bulk forming * High fiber * Absorbs water to increase bulk * Distends bowel to initiate reflex bowel activity Examples: * psyllium (Metamucil) * methylcellulose (Citrucel) * polycarbophil

Improve stool consistency and frequency with regular use Ensure good fluid intake to prevent faecal impaction Onset of action 2-3 days Side Effects may include bloating, flatulence, distension

Mosby items and derived items © 2005, 2002 by Mosby, Inc. 2. Emollient * Stool softeners and lubricants * Promote more water and fat in the stools * Lubricate the fecal material and intestinal walls Examples: * Stool softeners: docusate salts (Colace, Surfak) * Lubricants: mineral oil

* Stool softener may take days to become effective. * They should not be taken together with mineral oil because of the potential for absorption of the mineral oil. * Lubricant laxatives include Mineral oil and glycerin suppositories. * They facilitate the passage of hard stools. * Mineral oil should be taken orally in an upright position to avoid its aspiration and potential for lipid or lipoid pneumonia.

Mosby items and derived items © 2005, 2002 by Mosby, Inc. 3. Hyperosmotic * Increase fecal water content * Result: bowel distention, increased peristalsis, and evacuation Examples: * polyethylene glycol (GoLYTELY) * sorbitol * glycerin * lactulose (Chronulac)

* PEG powder for solution is available as a prescription and also an over-the-counter laxative. * Lactulose is a semisynthetic disaccharide sugar that also acts as an osmotic laxative. It is a product that cannot be hydrolyzed by intestinal enzymes. Oral doses are degraded in the colon by colonic bacteria into lactic, formic, and acetic acids. This increases osmotic pressure, thereby accumulating fluid, distending the colon, creating a soft stool, and causing defecation.

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Saline * Increase osmotic pressure within the intestinal tract, causing more water to enter the intestines * Result: bowel distention, increased peristalsis, and evacuation

Mosby items and derived items © 2005, 2002 by Mosby, Inc. Saline laxative; saline cathartic; examples: * magnesium sulfate (Epsom salts) * magnesium hydroxide (MOM) * magnesium citrate * sodium phosphate (Fleet Phospho-Soda, Fleet enema)

* Saline cathartics are nonabsorbable salts (anions and cations) that hold water in the intestine by osmosis and distend the bowel. * increasing intestinal activity and producing defecation in a few hours. * Electrolyte solutions containing polyethylene glycol (PEG) are used as colonic lavage solutions to prepare the gut for radiologic or endoscopic procedures.

Mosby items and derived items © 2005, 2002 by Mosby, Inc. 4. Stimulant * Increases peristalsis via intestinal nerve stimulation Examples: * castor oil * senna * cascara * bisacodyl

* Senna is a widely used stimulant laxative. * Its active ingredient is a group of sennosides, a natural complex of anthraquinone glycosides. * Taken orally, it causes evacuation of the bowels within 8 to 10 hours. * It also causes water and electrolyte secretion into the bowel. * In combination products with a docusate- containing stool softener, it is useful in treating opioid-induced constipation.

* Bisacodyl, available as suppositories and enteric- coated tablets, is a potent stimulant of the colon. * It acts directly on nerve fibers in the mucosa of the colon. * Adverse effects include abdominal cramps and the potential for atonic colon with prolonged use. *.

* Antacids should not be taken at the same time as the enteric-coated tablets. The antacid would cause the enteric coating to dissolve prematurely in the stomach, resulting in stomach irritation and pain. * The same adverse effects could be expected with milk, H2-receptor antagonists, and PPIs

* Castor oil is broken down in the small intestine to ricinoleic acid, which is very irritating to the gut, and promptly increases peristalsis. * It should be avoided by pregnant patients, because it may stimulate uterine contractions.

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * Bulk forming * Impaction * Fluid overload * Emollient * Skin rashes * Decreased absorption of vitamins * Hyperosmotic * Abdominal bloating * Rectal irritation

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * Saline * Magnesium toxicity (with renal insufficiency) * Cramping * Diarrhea * Increased thirst * Stimulant * Nutrient malabsorption * Skin rashes * Gastric irritation * Rectal irritation

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * All laxatives can cause electrolyte imbalances!

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * Obtain a thorough history of presenting symptoms, elimination patterns, and allergies * Assess fluid and electrolytes before initiating therapy * Patients should not take a laxative or cathartic if they are experiencing nausea, vomiting, and/or abdominal pain

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * A healthy, high-fiber diet and increased fluid intake should be encouraged as an alternative to laxative use * Long-term use of laxatives often results in decreased bowel tone and may lead to dependency * All laxative tablets should be swallowed whole, not crushed or chewed, especially if enteric coated

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * Patients should take all laxative tablets with 6 to 8 ounces of water * Patients should take bulk-forming laxatives as directed by the manufacturer with at least 240 mL (8 ounces) of water

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * Bisacodyl and cascara sagrada should be given with water due to interactions with milk, antacids, and H2 blockers

* Patients should contact their physician if they experience severe abdominal pain, muscle weakness, cramps, and/or dizziness, which may indicate possible fluid or electrolyte loss

Mosby items and derived items © 2005, 2002 by Mosby, Inc. * Monitor for therapeutic effect