Constipation Flashcards
What is the effect of constipation to quality of life?
If it is everyday, constipation can reduce quality of life similar to having osteoporosis or diabetes
How do the nervous system and hormones impact the GI tract?
PNS (stimulate motility)
SNS (inhibit motility)
GI hormones
Serotonin
CNS (emotions)
What is gastro-colic reflex?
30 min after a morning meal, humans will naturally excrete feces (this can be suppressed by holding feces in)
Patients can make their gastric-colic reflex stronger
What is the range of normal bowel movements?
Wide range: 2x per week to 3x per day
Are regular enemas useful in removing normal poop during good health?
No, your body has the mechanisms to take care of it
How much water flows through the duodenum?
9L enters the duodenum/day
How much of the water that flows through the duodenum comes from the diet?
2L from diet (includes food and water)
How many litres of water that flow through the duodenum come form intestinal secretions?
7L
How much water is absorbed by the Gi tract per day?
Out of the 9L that enters via the duodenum, 8L are absorbed
From the remaining 1L, 850mL are absorbed by the large intestine
This effectively leaves 150mL of water/day released via feces
Is constipation a normal part of aging?
No, constipation is seen in many older adults, but it is not normal
It can be caused by the following reasons:
Disease states
Drug adverse effects
Immobility
Fluid intake (maybe?)
Is there a normal bowel movement schedule?
Not really, each person has their own normal
Less than 50% of people have one bowel movement/day. Most people have an irregular schedule (do not have a bowel movement everyday)
What are are some complications of constipation?
Hard stools
Anal fissures
Anal tears
Rectal bleeding
Hemorrhoids
Abdominal discomfort and swelling
Abdominal pain
Bloating
Aggravation of hernias
Are most cases of constipation severe?
No, but we still have to be cautious
What are some GI conditions pharmacists should know how to differentials diagnose?
Anal fissure (seen in kids who hold poop, withholding behaviour)
Medication-induced constipation
Diabetes mellitus (lower nerve control)
Colon cancer
When should we get worried about the last time they had a bowel movement?
Longer than 3 or more days without one
What are some red flags that warrant MD referral in constipation?
Changes in stool texture
Blood in stool
Hemorrhoids
Weight loss
Decreased appetite
Nausea
Vomiting
Constipation that lingers for three weeks
What is a large bowel obstruction?
It occurs when part or all of the large intestine is blocked
What can cause a large bowel obstruction?
Large bowel obstruction can occur due to the following reasons:
Growth or tumour that blocks intestine
Twisting of the bowel (volvulus)
A narrowing (stricture) of the bowel, caused by scar tissue from conditions such as diverticulitis and Crohn’s disease
What are the symptoms of a large bowel obstruction?
These symptoms are more than what is seen in normal constipation
Belly cramping and pain
Belly swelling and bloating
Unable to pass gas
Unable to pass stool (constipation)
Vomiting
What are some non-pharmacological treatments for constipation?
Fluids
Exercise
FIber
When fluid is reccomended, does it mean well hydrated patients should drink even more water?
No, maintain normal hydration
Add fluid only if patient is chronically dehydrated
What diet modification can help reduce constipation?
Increasing fiber in the diet will improve constipation
Men need 38 g of fiber, women need 25g
Is soluble fiber better for constipation vs. insoluble fiber?
No, insoluble fibre is given credit for better impact
What is bowel re-training?
This is not done my pharmacists (usually nurses)
They attempt to strengthen the gastric-colic reflex that naturally occurs about 30 min following morning meal
How do prunes/dried plums help with constipation?
If constipation is cleared quickly, attribute it to the sorbital in prunes
If constipation took up to 3 days to resolve, give credit to the fibre content of prunes
Start with 4 prunes or 1/2 cup juice
What are bulk-forming agents?
These are used after patient has tried o introduce fiber into their diet without success
They are the DOC for prevention (PEG 3350), not for acute treatment
Bulk-forming agents are soluble fibres
(ex. Psyllium, Inulin, methyl cellulose, bran)
How do bulk-forming agents work?
They swell in intestinal fluids—>creates gel—> facilitate passage
Can usually take a few days to see effects
How much Metamucil (psyllium) should be started initially?
7g TID, and dose can be adjusted to ideal stool softness
Normal hydration is fine, but avoid dehydration
What is the incidence of psyllium-induced obstructions?
Very rare, likely due to inappropriate use
(Swallowing Metamucil pellets(now discontinued) without water. The pellets got stuck to the tissue due to it pulling water)
What are some symptoms associated with psyllium-induced obstruction?
Pain
Cramps
Nauseous
Can feel a mass
No fecal output
Is psyllium more effective vs. inulin for clearing constipation?
Yes, but inulin is more palatable
Psyllium thickens fluid (less palatable)
Are psyllium capsules recommended by pharmacists?
No, because the dosing frequency is high, go for powder instead (plus powder is cheaper)
What are stool softeners?
Effectively detergents /anionic surfactant (allow oily fecal matter and water to mix)
Ex. Docusate
How long do stool softers take to clear constipation?
Takes 1-2 days (3-5 days in some patients)
What is a contraindications with docusate (stool softener)?
Do not take docusate with mineral oil. The docusate can breakup the mineral oil and it can improve mineral oil absorption = enters the blood
What are the different types of docusate (stool softeners)?
The following have equivalent stool softening abilities (equipotent):
Docusate Na+: 100mg
Docusate Ca2+: 240mg
What is the role of lubricants in treating constipation?
Mineral oil is often ingested to soften fecal matter. Physicians do not like this agent
Can resolve constipation in about 6-8 hours
What are some problems with mineral oil use in constipation?
Anal seepage
Lipid pneumonia (drops from mouth can fall into the airways)
Possible decrease in absorption of fat soluble vitamins (unlikely)
What is the difference between heavy mineral oil and normal mineral oil?
The heavy mineral oil is less likely to stick on the throat. It will stay in the GI tract
What is the efficacy of mineral oil enemas?
They work very fast to clear constipation(within 30 min)
How do saline (osmotic) agents work in treating constipation?
Contains non-absorbable ions (Mg citrate, MgOH)
They remain in the gut, and water is drawn in due to osmostic pressure
Usually used as bowel evacuation
How much magnesium is needed to experience diarrhea (reverse constipation)?
Above 800mg of Mg has laxative effects
What makes milk of magnesia (osmotic) unpopular for constipation treatment?
Very chalky flavour
What is the earliest age at which an enema can be given?
2 years old, any patient younger should use a suppository
Why does a child under 2 have constipation?
What is the effect of Glycerin suppositories?
It has osmotic effect and a local irritant effect
Especially useful in very young children
Bowel evacuation within 30 min
What is the efficacy of lactulose syrup (osmotic)?
Can take 1-2 days to clear constipation
Even though it is made from sugar, most of it passes through the GI tract without absorption. Safe for diabetics
How is PEG 3350 used for constipation treatment?
It is useful in prevention therapy, and can take a few days to work
Start at 17g and titrate up as needed (adjust dose experimentally)
Use for 7 days unless MD instructs otherwise
Do not use in kids under 18 unless MD instructs otherwise
What is the DOC for constipation prevention?
PEG 3350, especially in older adults
What are some common stimulants used in constipation treatment?
Bisacodyl and Senna
What is the mechanism of action for stimulants in constipation therapy?
They are irritating to gut lining, promote GI motility
What are some side effects seen in stimulant use in constipation treatment?
They are minimally absorbed (no systemic symptoms)
Can experience diarrhea/cramps
What is the reason for the intentional overuse of stimulants in constipation treatment?
Patients with anorexia may use these agents to move food out of their system
What are some warnings for stimulant overuse?
Chronic use may produce hypokalemia or dehydration
Laxative dependence
Chronic constipation
Does chronic use of stimulants disrupt normal bowel function after going cold turkey?
No, new evidence suggests this does not happen
How should senna be dosed?
Initial dose: 8mg on first night
Increase by 1 tab every night until you are using 3 tabs/night
If patient still has constipation after 3 days of senna use, probe for cause
Can patients use Tylenol #3 (T3) and senna together to prevent opiate-associated constipation?
We can use them together to prevent onset of constipation, treatment is harder and needs higher doses of senna
Take 2 tabs/day until they come off T3s
Review Slide 76 for agents for constipation treatment
What are the most common rescue constipation treatments?
Senna
Bisacodyl
Milk of Magnesia
Likely not mineral oil
What are some common prevention agents for constipation?
PEG 3350
Docusate
What is Colyte?
It has added electrolytes and it contains PEG 3350
Expect bowel movement within an hour
What is the efficacy of probiotics in constipation?
No definitive product that has shown evidence for helping prevent constipation, no role in overnight treatment
What are some patient groups of interest when it comes to constipation?
Ambulatory elderly
Paediatrics
Pregnancy
Palliative Care
Who is an ambulatory elderly patient?
They usually have multiple disease states/medications
If the are old, they may also have a suppressed bowel reflex
What do pharmacists recommend to elderly patients for constipation?
Dietary measures (increase fiber)
Water’s value is iffy
PEG 3350 (Patient needs education on adjusting doses. The side effects for laxatives are overblown)
What are some natural options for elderly patients with constipation?
Prevention (increase fiber)
Acute relief (prune or dried plums)
What are the most common constipation therapies used in the elderly?
Any of the following can be used together as long as their respective dosing instructions are followed
Prevention:
Bulk-forming agents
Docusate
PEG 3350
Acute relief:
Senna
Review slide 95 for a treatment algorithm for constipation treatment in the elderly
When should pharmacists be worried about elderly patients with constipation?
Unexplained new onset/worsening
Blood in stools
Weight loss, anorexia
Fever
Nausea and vomiting
Family history of colorectal cancer
What is a normal bowel movement schedule for infants?
1 bowel movement per each feed to once per week
Bowel movement rate usually picks up after starting solid foods and start getting enough fluids
How to tell if a baby is constipated?
The baby is likely to be constipated if the baby cries
What are some paediatric (infants) treatments for constipation?
Always have MD referral in mind (less likely to recommend a product)
Rectal stimulation via applying Vaseline on anus with q-tip
Glycerin suppository
What causes constipation in toddlers?
Too busy to poop (leads to withholding behaviour due to large and hard poop)
Dietary issues
Toilet training issues (placed legs on a stool, will help feces leave the body)
Can any of the adult constipation products be used in paediatrics?
Yes, none of them are contraindicated in paediatrics
What is the dosing for PEG 3350 in paediatrics?
Start with 1/2 capful and titrate up
PEG3350 can take a few days to work (prevention agent)
How many women are constipated during pregnancy?
50% of women
Are iron supplements the main cause of constipation in pregancy?
Probably not, it is likely due to all of the changes associated with pregnancy
What are some good agents for constipation therapy in pregnant women?
Docusate is very common (should unload a few days before)
PEG 3350
Psyllium
*senna and bisacodyl are not recommended because the could cause uterine contraction concerns
How many patients on opiates have constipation?
40-90%, and these patients will not see a decrease in the severity of constipation
They start to reduce opioid dose to help reduce constipation. They are in pain because their constipation is too overbearing
Should senna and opioids be combined to prevent constipation?
Yes, because it is easier to prevent than treat
What are some medications that cause constipatioon?
Opioid pain relievers
Antihistamines
TCAs
