64. Constipation

Question 1

what is constipation

Answer 1

It may be defined as defecation that is unsatisfactory because of infrequent stools (< 3 times weekly), difficult stool passage (with straining or discomfort), or seemingly incomplete defecation.

Question 2

differentials for constipation

Answer 2

lifestyle related (low fibre, low activity, low fluid intake)
idiopathic/functional

Gastro:
IBS
IBD

Neoplastic:
- colorectal cancer

Metabolic and endocrine:
- hypothyroid
- hyperparathyroidism (hypercalcaemia)

Question 3

History taking constipation

Answer 3

PC: constipation
HoPC and gastro system: gain understanding of their definition of constipation, how often (change from normal?), stool consistency (use bristol stool chart), any diarrhoea, vomiting, flatulence, blood, mucus, bloating, distension
Change in weight? Bone Stones, abdominal groans,
Renal system: change to water works
Red flags: blood, mucus, weight loss, weight gain
Any self-help measures or drug treatments tried?
DHx:
Opioids (including co-codamol and dihydrocodeine)
Anticholinergics (includes tricyclic antidepressants, oxybutynin)
Verapamil
Clozapine (can be life threatening, see guidance here)
Aluminium containing antacids
Iron and calcium containing preparations.
SHx: activity levels, diet, the severity and impact of symptoms on daily life and functioning.

Question 4

Examination constipation

Answer 4

Abdo exam (tenderness, amsses, imapction)
DRE (any fissures, rectal masses, soft stool?hard stool?

Question 5

Investigations constipation

Answer 5

Bedside
Abdominal exam
DRE

Bloods
FBC for anaemia
Serum U&Es
Calcium
Thyroxine (T4)
Glucose

Question 6

Management chronic constipation

Answer 6

Counselling 1. advice on lifestyle measures
increasing dietary fibre
ensuring adequate fluid intake
ensuring adequate activity levels

Pharmacological
first-line laxative: bulk-forming laxative first-line, such as ispaghula
second-line: osmotic laxative, such as a macrogol (if hard)
Stimulant laxative eg senna (if soft)

if frail, consider softner first

Question 7

when should you stop taking laxatives?

Answer 7

Advise the person to gradually reduce and stop laxatives once the person is producing soft, formed stool without straining at least three times per week.

Question 8

Management opiod induced constipation

Answer 8

1. Osmotic laxative eg lactulose PLUS stimulant laxative eg senna

Question 9

Management acute constipation eg recent illness, immobility etc

Answer 9

1. Senna (stimulant)

Question 10

Management ibs constipation

Answer 10

1. Docusate (softener)

Question 11

what laxative should you avoid ibs

Answer 11

lactulose

Question 12

what laxatives should you avoid opioid induced

Answer 12

Do not prescribe bulk-forming laxatives.

Question 13

specialist management of refractory constipation

Answer 13

prucalopride (specialist prescribed)

consider if at least two laxatives from different classes have been tried at the highest tolerated recommended doses for at least 6 months, and failed to relieve symptoms, where invasive treatment (such as suppositories, enemas, rectal irrigation and/or manual disimpaction) is being considered.

Question 14

complications of constipation

Answer 14

overflow diarrhoea
acute urinary retention
haemorrhoids

Question 15

name a bulk forming laxative

Answer 15

ispaghula husk

Question 16

name a softner laxative

Answer 16

docusate

Question 17

name 2 stimulant laxative

Answer 17

senna
bisacondyl

Question 18

name 2 osmotic laxative

Answer 18

macrogol
lactulose

Question 19

when to not prescribe bulk forming

Answer 19

flatulence and bloating. Excessive doses or inadequate fluid intake may cause intestinal obstruction.

Question 20

consideration macrogol

Answer 20

Macrogol laxatives can cause medications taken one hour before, during and one hour after to be flushed out of the gastrointestinal tract unabsorbed which includes contraceptive pills.

Question 21

should you use two laxatives at the same time

Answer 21

NOT of same class

YES of different classes (synergistic

Question 22

what to consider if diarrhoea on laxatives

Answer 22

impaction and overlfow

Question 23

second line chronic constipation (after bulk forming)

Answer 23

add macrogol

Question 24

define faecal loading

Answer 24

retention of faeces to the extent that spontaneous evacuation is unlikely

Question 25

presentation faecal loading

Answer 25

PC: Hard, lumpy stools, which may be large and infrequent
or small and relatively frequent
Overflow faecal incontinence, or loose stool.

Question 26

what does manual evacuation constipation - a finger having to be inserted into the vagina

Answer 26

rectocele

Question 27

Management faecal loading

Answer 27

1. Macrogol (osmotic)
2. Add oral stimulant eg senna
3. Enema or suppository
   A suppository such as bisacodyl for soft stools; glycerol alone, or glycerol plus bisacodyl for hard stools.
   A mini enema such as docusate (softener and weak stimulant) or sodium citrate (osmotic).

Question 28

complications laxative abuse

Answer 28

low potassium, low sodium, dehydration

Question 29

contraindications to stimulant laxatives

Answer 29

cramping, colitis, bowel obs etc