What is the ROME IV criteria for functional/chronic constipation?
- Must include 2 or more of the following for at least 3 months with an onset of at least 6 months prior to diagnosis:
- straining
- lumpy or hard stools (Bristol 1-2)
- sensation of incomplete evacuation
- sensation of anorectal obstruction
- <3 movements/week
- manual maneuvers to facilitate more than 25% of defacations - Loose stools are rarely present without use of laxatives
- Insuficient criteria for IBS
***discomfort and not PAIN
What are some presenting symptoms of IBS-C that will distinguish it from constipation?
- bloating and pain
- painful constipation may be identifying feature occurring 1 day/week over the past 3 months
What is fecal impaction and what are some of the symptoms of it?
Fecal impaction = inability to pass a hard collection of stool
Symptoms:
- rectal discomfort
- anorexia
- nausea
- vomiting
- abdominal pain
- urinary frequency
***physically or mentally incapacitated persons and the elderly are at particular risk of impaction
What are some of the medications that could contribute to chronic constipation?
- anticholinergics
- antidepressants
- antiepileptics (gabapentin, pregabalin)
- antiplatelets
- antipsychotics
- Diuretics
- NSAIDs
- Vinca alkaloids
What are the goals of therapy for constipation? (7)
1) treat or correct cause of constipation
2) return frequency of stool to normal or minimum >3/week
3) eliminate symptoms of straining, incomplete emptying, bloating, pain and obstruction
3) improve stool consistency
4) avoid complications (hemorrhoids, anal fissure, rectal prolapse, impaction)
5) treat fecal impaction or obstruction
6) use laxatives appropriately and AVOID DEPENDENCY
7) improve quality of life
What are the s/s of constipation?
- infrequent defecation
- abdominal distention
- N/V
- anorexia
- small stools that are hard and difficult to evacuate
- incomplete rectal emptying
- weight loss (in chronic constipation)
What are the red flag s/s requiring further assessment of a patient presenting with constipation?
- children <2 years
- constipation lasts >2 weeks or no bowel movement for 7 days despite use of laxatives
- blood or mucus in stool, rectal bleeding, fever
- family history of colon cancer (esp if patient is >50)
- persistent abdominal pain
- vomiting
- severe pain upon defecation
- unremitting nocturnal symptoms
- diarrhea alternating with constipation
- recent abdominal surgery
- moderate to extreme thirst
- unexplained weight loss >5%
- rectal or abdominal mass
What are some strategies to prevent constipation?
- consume high fiber diet with ~1500mL of fluid/day
- regular, private toilet routine
- heed urge to defecate
- take prophylactic medication if using constipating medication or if patient has disease associated with constipation
- moderate daily physical activity, particularly with the elderly
What is the dietary fiber intake recommended for adult females, adult males, pregnant females, and children?
Female = 25g
Male = 38g
Pregnant/breastfeeding = 28/28g
Children = >10g for 3-7, >15 for 8-14
List some vegetables that are high in fiber
- artichoke hearts
- beans (pinto and red kidney)
- chickpeas
- lentils
- green peas
List some fruits that are high in fiber
- avocado
- blackberries
- plum
- prune
- raspberries
What are some non-pharmacological options for the management of constipation for adults? (7)
- increase calories if low caloric intake; improves colonic transit
- have a regular bowel regimen; same time very day, especially after breakfast, heed the urge to defecate, avoid prolonged periods on the toilet
- consume high fiber diet 25-38g; soluble fiber is better
- eat more fruits; contain natural laxative sorbitol
- exercise
- lose weight in overweight patients; statistical benefit not shoen but still recommend
- biofeedback and relaxation
What are some non-pharmacologic options in the management of constipation in children?
- increase fiber in diet
- prune, apple and pear juice 1-3mL/day in children 6-12 months
- restrict dairy intake, suggest soy milk
- normal level of physical activity
- behavioural therapy; encourage to attempt defecation 5-10 minutes after each meal until a bowel movement happens that day
what is the cycle of constipation?
constipation –> accumulation of feces –> increased diameter of Gi tract –> effectively reduces function of GI tract –> time taken to pass increases –> constipation
What are the categories of laxatives? (5)
- bulk-forming
- emollient/stool softeners
- osmotic
- stimulant
- saline laxatives
Bulk-forming laxatives - list examples, brand names, MOA, safety, efficacy, instructions for use
Examples:
Psyllium/Metamucil
Wheat Dextran, Inulin/Benefiber
MOA: increases stool volume and stimulates motility
Instructions: take with AT LEAST 250mL of water/juice
Safety/Efficacy: safest agents suitable for long term use, not enough evidence for calcium polycarbophil and methylcellulose although still recommended if patient cannot tolerate other bulk-forming laxatives
Emollients/stool softeners - list an example, proposed MOA and efficacy/safety.
Example: docusate sodium
MOA: act as a surfactant to soften the stool by allowing the mixing of aqueous and fatty substances
Efficacy/safety: weak anecdotal evidence, does not improve symptoms of chronic constipation, heavy mineral oil is not generally recommended although studies in pediatric patients have shown superiority to senna-based laxatives but inferior still to osmotic agents
Osmotic laxatives - list examples, MOA, safety/efficacy and dosage forms
Examples: PEG and Lactulose
MOA: create an osmotic gradient and retain water in the intestinal lumen, increased pressure on lumen wall induces gastric motility
Efficacy/safety: effective and well tolerated (PEG>lactulose), daily use of PEG is safe and effective for up to 6 months, possible to experience diarrhea, best used regularly rather than as needed (require 24-72 hours for onset)
- safe for use in diabetics
Glycerin suppositories act osmotically and have a fast onset of action 15-30 minutes, less effective if stool is dry/hard or high in colon
What is the second line osmotic laxative and why?
Milk of magnesia –> frequent diarrhea, electrolyte abnormalities, must be administered with sufficient water to avoid dehydration
Lower level of evidence
Should only be used in patients with normal renal function
Purgatives - what is safe and effective, what isn’t?
High volume PEG with electrolytes or low volume PEG without electrolytes = safe and effective when used at high doses for purging
- **repeated or prolonged use may result in electrolyte imbalance
- *Caution in patients with renal impairment, taking diuretics and pediatric or geriatric patients
UNSAFE FOR PURGING = oral sodium phosphate
Stimulant laxatives - list some examples, MOA, efficacy/safety, AEs and onset of action
Examples: Bisacodyl, senna, sodium picosulfate
MOA: increases colonic peristalsis by producing rhythmic muscle contractions in the intestines
Efficacy: may be recommended if osmotic laxatives fail or are not tolerated, bisacodyl has moderate evidence, low quality evidence supports senna, treatment of choice for opioid induced constipation
Safety: likely safe in chronic constipation
AE: abdominal cramping; higher with bisacodyl
Onset: take at bedtime due to 6-12 hour delay in onset
Can castor oil be recommended as an alternative stimulant laxative?
No longer recommended
Contraindicated in pregnant and elderly patients, produces abdominal cramping and pain, can be aspirated and stimulates uterine contractions during pregnancy
Enemas - List the type of constipation used for, onset, safety/efficacy and instructions for use
Useful and effective for the treatment of acute constipation and as means for cleansing distal colon for endoscopic/surgical procedures
Onset: faster than suppositories, <15-30 minutes and produce cleansing within 1 hour of administration
Safety: associated with increased mortality in the elderly
Instructions:
- lubricate enema nozzle if not already pre-lubricated
- lie on left side with knees bent
- insert enema nozzle into rectum with nozzle pointing towards navel
- gently squeeze container until dose is expelled
- if discomfort is felt, flow is too fast
- retain solution until definite abdominal cramping is felt
What is the efficacy of using probiotics in the management of constipation?
Meta-analysis showed mean increase in stool frequency and reduction of intestinal transit time
Lack of heterogeneity in products makes it difficult to determine most beneficial strains, dosage, frequency and duration of treatment
