Chapter 32 - Constipation

Question 1

What does constipation mean to the patient?

Answer 1

Constipation as lots of different definitions:

straining
hard/infrequent stools
pain during BMs,

Question 2

what defines chronic constipation?

Answer 2

Constipation >3 months

Question 3

What’s obstipation?

Answer 3

Constipation + inability to pass flatus

Question 4

What are some risk factors for constipation?

Answer 4

Women 
Elderly 
low SES
high BMIs
Low fiber 
sedentarysm 
multiple medication

Question 5

What are the causes of constipation?

Answer 5

1) Primary 
congenital / structural 
a) Hirschprung's disease 
b) imperforate anus 
c) anorectal atresia 
d) IBS 

most common in paeds population

2) secondary
a) neurology
chronic: MS, Parkinsons disease
Acute: spinal cord injury

b) metabolic 
muscles need electrolyes, sugars and hormones to work 
- diabetes 
-hypercalcemia/hypokalemia/hypomagnesia
-hypothyroidism  

c) myopathies
- systemic sclerosis/ amyloidosis

d) Strucstural
- tumour or stricture
- intussusception
- rectocele/rectal prolapse

e) medication related
- opiates
- iron/calcium
- antidepressants
- diuretics
- antipsychotics
- anticholinergics
- antiepileptics
- antiparkinsons agents

f) Psych
abuse, eating disorders, affective disorders

g) other:
- dehydration/immobility/dietary factors
- pregancy
- post-op pain

Question 6

What is key in the history of someone with constipation? what are the red flags/alarm symptoms ?

Answer 6

Hx:

• usually tells you the dx
• thorough review of medications
• review OTC meds

Alarm symptoms:

• fever
• weight loss
• anorexia
• vomiting (obstruction)
• blood in the stool
• onset in age >50 years with new constipation without obvious culptrit: should have colonscopy to rule out mass

Question 7

What are key parts of hte physical exam?

Answer 7

1) abdominal exam
2) rectal exam:
- fissures, hemorrhoids, rectal prolapse
- DRE for masses, proctitis, gross blood

Question 8

What are some possible investigations for constipation?

Answer 8

1) very little blood work typically needed: i..e Hg for anemia, extended electrolytes, TSH?
2) X-ray is actually useless even for fecal impaction
3) need advanced imaging if severe abdo pain
4) should screen for colon CA in anyone over >50 yrs old

Constipation should be a diagnosis of exclusions

Question 9

What is the management of constipation?

Answer 9

1) Tx underlying contributing factors
- fissures (emolioid gel), abscesses
- withhold offending medications/OTC

2) Tx cocktail for everyone: 3F’s
a) fiber
b) fluids
c) fitness/exercise
d) agents for constipation

3) Tx agents for consitpation based on class:

Question 10

Describe the possible treatment agents for constipation in addition to the rest of the cocktail of daily healthy bowel regime?

Answer 10

1) bulking agents – fiber that is indigestible
a)Psyllium (metamucil)
– up to 20 g daily
WITH plenty liquids
b)Prunes,
c) figs

2)osmotic salts
a) Sodium phosphate
– 30 ml prn.
b) citrate – milk of magnesia – 30-45 ml daily

3) sugars
a) Lactulose –
b) PEG 3350 – 17 g BID
Golytely or miralax

4) stool softeners
a) Mineral oil – 5 – 15 ml qhs
b) colace 100 mg BID – of little use

5) stimulant laxatives
a) Senokot 8 – 34 mg daily (gut becomes dependent on it with long term use)

6) suppositories and enemas
- For poop in the rectum
a) Glycerin suppositories
b) Warm tap water enemas for large amounts of stool in the rectum

8) Fecal disimpaction for severe constipation

Question 11

What is the disposition?

Answer 11

1) people with medically necessary medications causing constipation - need regular regimen not temporary of anti-constipation meds

2) in palliative patients on narcotics:
- methylnatrexone for blocking the opioid receptors in the gut therefore improving constipation but not blocking the central opioid receptors thereby not affecting pain control