209 Constipation and IBS Flashcards Preview

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Flashcards in 209 Constipation and IBS Deck (46):
1

What is primary (functional) constipation?

Dysmotility due to mechanical problem
Never learnt

2

What is secondary (organic) constipation?

Constipation due to obstruction

3

What is obstruction defaecation syndrome?

Constipation perhaps due to chronic straining producing a stretching and redundancy of the distal rectum where compensation methods have ceased and evacuation has become impaired

4

Name 3 causes of idiopathic constipation

IBS
Slow transit
Megacolon/megarectum

5

Name 2 metabolic causes of chronic constipation
(3 listed)

Hypothyroidism
Hypercalcaemia
Hypokalaemia

6

Name a neuromuscular disease which can cause chronic constipation

Hirschsprungs

7

How can anorectal physiology be assessed/investigated?

Manometry
Balloon inflation - i.e. rectal sensation studies

8

What does 5 or fewer markers remaining on day 5 (AXR) following colonic transit studies suggest?

Normal GIT transit

9

Why do pts with DM become constipated?

Due to chronic dysmotility and slow transit

10

Which CNS diseases can develop constipation?
(4 listed)

Parkinsons
MS
CVA
Spinal injuries

11

Name 4 types of drugs which can cause constipation
(7 listed)

Narcotics
Iron supplements
Non magnesium antacids
Calcium channel blockers
Inadequate thyroid hormone replacement
Psychotropic drugs
Anticholinergic drugs

12

What diagnostic criteria is used to diagnose IBS?

Rome II

13

What is the MOA of bulk forming laxatives?

Retain fluid in stool to increase faecal mass and stimulate peristalsis and soften stool

14

What is the MOA of osmotic laxatives?

Increase the fluid in the large bowel --> producing distension leading to stimulation of peristalsis.
Also has stool softening properties

15

What is the MOA of stimulant laxatives? (esp Senna)

Stimulate colonic and rectal nerves.
Senna is hydrolysed in the large bowel by bacteria into active metabolite

16

What is the MOA od surface-wetting agents?

Reduce the surface tension of of the stool allowing water to penetrate and soften it

17

What are fcyclomine and hyoscine used for in chronic constipation?

Pain management - they're antispasmotics.
Relaxes SM but might aggravate the constipation

18

How may antidepressants help constipation?

Affect serotonergic signalling but have variable anticholinergic activity

19

When would patients taking probiotics typically see an improvement in their constipation?

Within 6 weeks

20

What type of drug is Lubiprostone? (treatment of constipation)

Chloride channel activator - works in the luminal side to stimulate chloride secretion and water secretion into the lumen - soften stool, increase motility and promote spontaneous bowel movement

21

What are the 3 surgical options for dysmotility?

1. Colectomy and iliorectal anastomosis
2. SNS (sacral nerve stimulation)
3. ACE procedure - antegrade colonic enema

22

What is the important consideration when deciding about colectomy (functionally)?

Normal small bowel motility - incase of need of temporary ileostomy.

23

What is SNS used for?

Faecal incontinence

24

What causes obstructed defaecation?

Chronic straining producing stretching and redundency of the distal rectum + pelvic problems

25

What commonly precedes rectocoele causing obstructed defaecation?

Childbirth

26

What are the 3 indications for surgery to treat obstructed defaecation?

External prolapse
Rectocoele
Rectal intersusseption

27

Which Surgery is more suitable for older patients to treat obstructed defaecation?

- Open rectopexy
- Perineal procedure

Perineal procedure

28

Which imaging method is 90% sensitive for lesions >1cm?

CT colonography

29

Which imaging method is good for visualising the mesorectal fascia?

MRI

30

Which imaging technique is useful for functional imaging of tumours?

PET scan

31

What does adenoma in the colon look like?

Cauliflower

32

Where are mets usually found with colorectal cancers?

Liver and lungs

33

Which important structure is commonly involved in rectal cancer?

Mesorectal fascia

34

What is T1 stage rectal cancer?

Confined to the mucosa + muscularis mucosa must be intact

35

What is T2 stage rectal cancer?

Submucosa and mucosa also compromised

36

What is T3 stage rectal cancer?

Cancer extending beyond the muscularis mucosa

37

What is T4 stage rectal cancer?

Involvement of other organs/structures

38

What is ERUS?

Endorectal ultrasound

39

What are the downfalls of ERUS?

Sometimes cant pass the probe
Field of view small
Operator dependant

40

What is the initial treatment of constipation?

Dietary and fluid intervention

41

What is the daily recommended intake of fibre?

18-30g

42

What pharmacological intervention is the 1st line treatment after dietary and fluid intervention has been unsuccessful in the treatment of constipation?

Bulk forming laxatives

43

What is the secondary pharmacological treatment if bulk forming laxatives have been unsuccessful in the treatment of constipation?

Osmotic laxatives ( if the stool remains hard)

44

When should a stimulant laxative be prescribed?

If the stool has softened but patient still finds them difficult to pass or complains of inadequate emptying

45

When should the macrogol, Arachis oil enema not be used?

If the patient has a peanut allergy

46

When should the macrogol, phosphate enema be used with caution?

When renal impairment or HF