constipation

Question 1

symptoms of constipation

Answer 1

decreased frequency of BO 
hard, dry stools 
straining 
abdominal bloating 
feeling of incomplete bowel movement 
feeling like having to pass a bowel movement but not able to

Question 2

causes of constipation

Answer 2

lifestyle:
travel, inadequate dietary fibre and or fluid intake
physical inactivity, parent child interactions, holding back urge to defecate

medical causes:
drug induced (opioids, anticholinergic drugs, CCB, calcium and iron supplements etc) 
neurogenic causes, mechanical obstruction, metabolic conditions, psychogenic causes, pregnancy, pain, age

Question 3

things to ask

Answer 3

age and other demographic factors
onset/duration and history
associated symptoms: abdominal discomfort, bloating, straining
specific symptoms: stool quality, exact location of discomfort, severity of symptoms
usual stool habits
medication/medical history
changes in lifestyle associated with onset
what has been tried? how long?

Question 4

when to refer

Answer 4

<2yo
marked abdominal pain/discomfort 
n/v
bloody/black or tarry stools 
fever 
unexplained changes in bowel habits esp if accompanied by weight loss 
change in stool caliber 
symptoms > 1 week with laxatives or >2 weeks if self treat 
suspect medication

Question 5

types of fibre/bulk forming laxatives (2)

Answer 5

isphaghula husk (fybogel) 
sterculia

Question 6

MOA of bulk forming

Answer 6

reduced stool consistency by increasing retention of water in stool
increased stool volume
improves passage of feral material

Question 7

onset of bulk forming

Answer 7

up to 72 hours

Question 8

how to administer bulk forming

Answer 8

taken with food

stir contents into glass of cold/room temperature water and drink immediately

Question 9

contraindications for bulk forming

Answer 9

intestinal obstruction

fecal impaction

Question 10

SE for bulk forming

Answer 10

flatulence/bloating
esophageal/colonic obstruction
interfere absorption of drugs
psyllium may cause allergic reaction

Question 11

lubricant laxative example

Answer 11

liquid paraffin

Question 12

lubricant laxative moa

Answer 12

coat decal matter with oil –> prevents water from leaving faces

Question 13

lubricant laxative onset of action

Answer 13

6-8h

Question 14

lubricant laxative administration

Answer 14

avoid taking within 2h of meals

Question 15

contraindication for lubricant laxative

Answer 15

abdominal pain 
n/v present 
gerd 
bed-ridden 
dysphagia

Question 16

precaution for lubricant laxative

Answer 16

do not recommend for elderly, preggo or <6yo

Question 17

SE of lubricant laxative

Answer 17

may impede absorption of fat solution vitamins 
interfere absorption of drugs 
unpleasant taste 
anal seepage 
lipid pneumonia

Question 18

stimulant laxatives (2)

Answer 18

Senna

bisacodyl

Question 19

Senna dose

Answer 19

7.5mg (2 tabs on)

max 70-100mg/day, divided bd

Question 20

Senna moa

Answer 20

stimulates nerve plexus of intestinal smooth muscle
increase peristalsis
decrease reabsorption of water and electrolytes from colon

Question 21

Senna onset

Answer 21

6-12 hours PO

Question 22

Senna contraindications

Answer 22

acute inflammation (eg churns)
bowel obstruction/fecal impaction
n&v
<12yo

Question 23

Senna SE

Answer 23

abdominal cramps, n&v
diarrhoea
hypokalemia, dehydration
melanosis coli, discolours urine

Question 24

bisacodyl onset

Answer 24

PO: 6-12h
Supp: 15-60min

Question 25

bisacodyl dosage

Answer 25

enteric coated: 5-15mg single dose. max 30mg for bowel evacuation suppository: 10mg single dose

Question 26

bisacodyl administration

Answer 26

space from milk, antacids, avoid with cimetidine

Question 27

bisacodyl SE

Answer 27

abdominal cramps, n&v, diarrhoea hypokalaemia, dehydration cathartic colon with chronic use?

Question 28

osmotic laxatives (5)

Answer 28

``` lactulose polyethylene glycol magnesium sulfate sodium phosphate glycerin ```

Question 29

lactulose MOA

Answer 29

non-absorbed disaccharides are metabolised by colonic back into organic acids increase osmotic pressure (draws fluid into GI lumen --> softens stool, distends lumen and promotes peristalsis) prebiotic: strengthens growth of some bacteria while suppressing potentially pathogenic bacteria lowers pH

Question 30

lactulose onset

Answer 30

24-48h

Question 31

lactulose SE

Answer 31

abdominal cramping, flatulence, bloating, diarrhoea

Question 32

polyethylene glycol MOA

Answer 32

retains water in intestinal lumen by creating an osmotic gradient

Question 33

polyethylene glycol SE

Answer 33

bitter taste, incontinence, diarrhoea

Question 34

magnesium sulfate dose

Answer 34

5-15g in a glass of water + another glass of water

Question 35

magnesium sulfate MOA

Answer 35

retains water in the intestinal lumen by creating an osmotic gradient

Question 36

magnesium sulfate onset

Answer 36

30min-3h

Question 37

magnesium sulfate indication

Answer 37

bowel cleansing before medical procedures

Question 38

magnesium sulfate contraindication

Answer 38

severe renal impairment congestive cardiac failure GI obstruction N&V

Question 39

magnesium sulfate precaution

Answer 39

drink as much fluids as possible | minimum 9 glasses to prevent dehydration

Question 40

glycerin suppository dosage

Answer 40

<6yo: 1-1.5g | >6yo: 3g

Question 41

glycerin suppository onset

Answer 41

15-60min

Question 42

glycerin suppository precaution

Answer 42

avoid in conditions involving rectal irritation (eg piles)

Question 43

glycerin SE

Answer 43

rectal irritation

Question 44

phosphate enema adult dose

Answer 44

133ml

Question 45

phosphate enema paediatrics dose

Answer 45

66.6ml

Question 46

phosphate enema moa

Answer 46

mechanical lavage

Question 47

phosphate enema onset

Answer 47

5-15min

Question 48

phosphate enema administration

Answer 48

not more than 1 in 24h

Question 49

phosphate enema precaution

Answer 49

risk of colonic peforation, rectal gangrene, hyperphosphatemia, hypocalcemic tetany chronic use can lead to loss of rectal tone and focal incontinence avoid in renal impairment and CHF