Constipation and bowel cleansing Flashcards Preview

A - BNF: CHAPTER 1 GI > Constipation and bowel cleansing > Flashcards

Flashcards in Constipation and bowel cleansing Deck (28)
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1
Q

Constipation is

A

the EVACUATION OF HARD STOOLS LESS FREQUENTLY THAN IS NORMAL for an individual.

  • It can occur at any age and is commonly seen in women, the elderly and during pregnancy.
2
Q

Constipation lifestyle advice

A

Fibre intake, adequate fluid intake and exercise is advised. Fruits high in fibre and sorbitol, and fruit juices high in sorbitol can help prevent and treat constipation.

3
Q

Laxative abuse

A

Laxative abuse can lead to hypokalaemia, so they should only be given if straining to defecate will exacerbate the condition e.g. angina.

4
Q

General side effect for all Laxatives is

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Abdominal pain

5
Q

Bulk-forming Laxatives - Examples include

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bran, ispaghula husk, methylcellulose and sterculia. They increase faecal mass causing peristalsis

6
Q

Bulk-forming Laxatives - onset of action is

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Onset of action is up to 72 hours. Adequate fluid intake must be maintained to avoid intestinal obstruction. Advise patients to not take immediately before bed.

7
Q

Stimulant laxatives - Examples include

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bisacodyl, sodium picosulfate, senna, co-danthramer and co-danthusate.

8
Q

Stimulant laxatives - onset of action

A

Very fast acting: Senna (8-12 hours), Bisacodyl (10-12 hours)

9
Q

Avoid stimulant laxatives in

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They increase intestinal motility, but often cause abdominal cramp, so avoid in intestinal obstruction.

10
Q

Co-danthramer and Co-docusate should only be used

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in the terminally ill, due to carcinogenicity and genotoxicity.

11
Q

Faecal softeners onset of action

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within 15 mins - fastest!

12
Q

Faecal softeners - These drugs increase

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penetration of intestinal fluid into the faecal mass –> Docusate sodium + Glycerol. An example is Arachis oil… hence peanut allergy.

13
Q

Faecal softeners example

A

Liquid paraffin has been used as a lubricant for the passage of stools, but manufacturer advises that it should be used in caution due to its adverse effects: anal seepage, risk of G.I. disease + pneumonia.

14
Q

Osmotic laxatives

These drugs increase & examples

A

the amount of fluid in the large bowel and a prime example is LACTULOSE. Interestingly, it can also be used to treat hepatic encephalopathy.
- Another example is macrogol 3350 with potassium chloride, sodium bicarbonate and sodium chloride.

15
Q

Managing Short-term constipation - 1st & 2nd line

A

1st Line: Bulk-forming laxative ensuring adequate fluid intake
2nd Line: If stools remain hard, add to or switch to an osmotic laxative
If stools are soft but difficult to pass/person complains of inadequate emptying, a Stimulant laxative should be added.

16
Q

Opioid induced constipation

A

 Osmotic laxative (or docusate sodium to soften stools) + Stimulant laxative is recommended
Bulk-forming laxatives

 Methylnaltrexone bromide + Naloxegol can be used when the response to other laxatives is inadequate. In palliative care, this drug should be used as an adjunctive to existing laxative therapy.

17
Q

Chronic constipation

Treatment should be started with

A

a bulk-forming laxative whilst ensuring good hydration.

If stools remain hard, add or change to an osmotic laxative such as macrogol. If macrogols are ineffective or not tolerated… Lactulose can be given.
If the response is inadequate, a stimulant laxative can be added.
 If atleast 2 laxatives from different classes have been tried at the highest tolerated doses for 6 months, the use of prucalopride (in women) should be considered.
 If regular bowel movements have been achieved, reduce and STOP 1 LAXATIVE AT A TIME. If possible, reduce the stimulant laxative first. But it may be necessary to also adjust the osmotic laxative dose to compensate.

18
Q

Constipation in pregnancy and breastfeeding

A

If dietary and lifestyle changes FAIL to control constipation in pregnancy, fibre supplements in the form of bran/wheat are clinically safe and effective.

A Bulk-forming laxative is first-line during pregnancy if fibre supplements fail. An osmotic laxative e.g. lactulose can also be used.

Bisacodyl or Senna can be used if a stimulant effect is necessary, but SENNA SHOULD BE AVOIDED NEAR TERM or if there is a history of unstable pregnancy.

 Stimulant are more effective than Bulk-forming laxatives… but they are more likely to cause side effects  diarrhoea and abdominal discomfort. Docusate and glycerol suppositories can be used.
 A bulk-forming laxative is first-line during breast-feeding, if dietary measures fail. Lactulose or Macrogol can be used if stools remain hard. As an alternative, a short course of stimulant laxative such as Bisacodyl or Senna can be used.

19
Q

Constipation in children

A

The first-line treatment for children with constipation is a laxative IN COMBINATION with dietary modification (juice containing sorbitol such as apple, pear or orange).

An increase in dietary fibre, adequate fluid intake and exercise is advised.

Diet should be well balanced and contain: fruits, vegetables, high-fibre bread, baked beans + wholegrain breakfast cereals.
Unprocessed bran can cause bloating, flatulence and reduced absorption of micronutrients.
 If faecal impaction is not present/been treated, first-line laxatives are a macrogol (e.g. macrogol 3350 with KCL, Sodium Bicarbonate and Sodium chloride).
 If there is an inadequate response/poorly tolerated add or change to a stimulant laxative
 If stools remain hard, lactulose or another laxative with softening effects e.g. docusate sodium can be added.

20
Q

Chronic constipation in Children

A
  • Laxatives should be continued for several weeks after a regular pattern of bowel movements.
  • The dose of laxatives should then be gradually tapered over a few months.
21
Q

Faecal impaction in children

A
  • In children over 1 years old, an oral preparation containing a macrogol (e.g. macrogol 3350 with potassium chloride, sodium bicarbonate and sodium chloride) is used to clear faecal mass + establish and maintain soft well-formed stools.
  • If disimpaction does not occur after 2 weeks a stimulant laxative can be added, or if stools are hard used in combination with an osmotic laxative such as lactulose.
22
Q

Osmotic laxative examples

A
  • lactulose
  • macrogol 3350
  • magnesium hydroxide
23
Q

Stimulant laxative examples

A
  • bisacodyl
  • senna
  • glycerol suppos.
  • docusate
  • co-danthrusate
  • co-danthramer
  • sodium picosulfate
24
Q

Opioid induced constipation -

A
  • naloxegol

- methylnaltrexxone

25
Q

Constipation red flags

A
  • new onset >50y, unexplained weight loss, anaemia, blood in stools, abdominal pain
26
Q

selective 5HT-4 agonist

A

Prucalopride

  • Used in women only when two or more laxatives have been used at the highest tolerated doses and not been effective for atleast 6 months.
27
Q

excessive stimulant use can cause

A
  • hypokalemia
  • lazy bowel
  • diarrhoea
28
Q

senna colour

A

colours urine brown/yellow