Constipation Flashcards
Where is stool stored?
The stool is stored in the rectum until the urge to defecate. The longer it is stored, the harder they become as more water is absorbed.
What is constipation?
The passage of hard stools, less frequently than the patient’s normal pattern.
What are the ‘statistics’ that define constipation?
- Opening bowels less than 3 times per week
- Straining to open bowels on 25% + of occasions
- Hard or pellet-like stools on 25%+ of occasions
What is chronic constipation?
If the symptoms have lasted greater than 12 weeks in the last 6 months
What gender is more likely to be constipated?
Females
What factors can cause constipation?
- Age- especially common over 65
- Diet- low fibre, high animal fat, high caffeine/alcohol intake
- Inadequate fluid intake
-Poor bowel habits- ignoring the urge to defecate - Medications e.g. antacids, antidepressants, iron, diuretics, painkillers, CCBs, ACE inhibitors, anticholinergics
- Abuse of laxatives
- IBS
- Travel
- pregnancy
- immobility e.g. bed rest
- poor thyroid function
What are the symptoms of constipation in children?
- Infrequent defecation
- Foul smelling stool
- increased flatulence
- Irregular stool texture
- Abdominal pain, distension, discomfort
- Soiling/ overflow
What happens to GI motility as you age and why?
As you age GI motility decreases as there is a decrease in elasticity and efficiency of the GI system.
- Also generally, mobility is reduced
- Poor diet- decreased fluid and food intake
- Wasting of pelvic floor muscles
- Side-effect of medications
What are the aims when trying to manage constipation?
- Achieve normal frequency of stools
- Regular, comfortable defecation
- Prevent laxative dependence
- Relieve discomfort
What is the bristol stool chart?
A medical aid used to classify stools in terms of their texture and shape/size.
Describe the 7 types of stools outlined in the bristol stool chart.
Type 1 = Separate, hard lumps, hard to pass
Type 2= Sausage shaped but lumpy
Type 3 = Sausage shaped, but with surface cracks
Type 4= Sausage or snake-shaped, smooth and soft
Type 5= Soft blobs with clear-cut edges passed easily
Type 6= Fluffy pieces with ragged edges, mushy
Type 7= Watery, no solid pieces, entirely liquid
What are some examples of bulk-forming agents?
Isphagula husk
Methylcellulose
What type of laxative is isphagula husk?
bulk forming
What type of laxative is methylcellulose?
bulk forming
What are some examples of stimulant laxatives?
Bisacodyl
Senna
Sodium picosulphate
What type of laxative is senna?
Stimulant
What type of laxative is bisacodyl?
Stimulant
What are some examples of fecal softeners?
Docusate
Glycerol suppository
Arachis oil (enema)
What type of laxative is docusae?
fecal softener
What are some examples of osmotic laxatives?
Lactulose
Magnesium hydroxide
Phosphate (suppository, enema)
What type of laxative is lactulose?
Osmotic
What is the difference in duration between acute and chronic constipation?
Acute = less than 4 weeks
Chronic = More than 4 weeks
What treatments would you suggest for constipation?
Lifestyle advice- increased exercise, fluid intake, fibre
- Bulk-forming laxative e.g isphagula husk
- Then can add an osmotic laxative e.g. macrogol
- stimulant laxative e.g senna
What is the difference between faecal loading and impaction?
Loading: Build up of faeces in the colon
Impaction: Material is present for a long time- water has been reabsorbed and so stool is hard to pass
If a patient is constipated and has hard stools, what laxatives would you recommend?
- High dose oral macrogol e.g. Laxido, movicol= draw water to the stool- try for 48 hours
- Can add a stimulant = e.g. senna or bisacodyl- aim to have movement within 12 hours, if response slow or inadequate:
- Add glycerol +/- bisacodyl suppository - bowel movement will usually be within 30 mins -1 hour
- If still inadequate- sodium picosulphate (powerful osmotic laxative) or arachis oil enema
If a patient is constipated but has soft stools, what laxatives would you recommend?
- Stimulant laxative e.g. Senna or bisacodyl (stool is already soft so don’t need a high dose macrogol to draw water to the stool like when stool is hard)
- Docusate or sodium citrate enema
What type of laxatives should be absorbed in opioid-induced constipation and why?
AVOID bulk forming laxatives!
As these increase the faecal mass causing the colon to be extended and stimulate peristalsis. However, opioids, decrease contractility and therefore peristalsis so has antagonist effects
What laxatives are recommended for opioid-induced constipation?
- Osmotic laxatives e.g. laxido, Movicol, docusate AND a stimulant laxative e.g. senna or bisacodyl
- If unsuccessful, can add a mu-opioid receptor antagonist e.g. Naloxegol, Naidemedine or methylnaltrexone
AVOID bulk-forming laxatives
What lifestyle advice should be offered to patients with constipation?
- Increase physical activity
- Increase fluid intake to a minimum of 2 L per day
- Increased fibre in diet- 30g of fibre per day
What laxatives should be recommended in pregnancy?
- Bulk-forming laxative
- Then can add or switch to an osmotic laxative if ineffective
- can consider a short-term stimulant e.g. senna but not close to term as can stimulate labour and has to be prescribed and not OTC (therefore, not really recommended)
Can pregnant women use stimulant laxatives e.g. senna?
Can consider a stimulant laxative for a short course e.g. senna but not close to term as can stimulate labour and has to be prescribed and not OTC (therefore, not really recommended)
What laxatives are recommended for use when breastfeeding?
- Bulk-forming
- Add or switch to osmotic
- Can consider a short course of stimulant laxatives e.g. bisacodyl, senna, glycerol suppository
What laxatives are recommended for use in children?
- Macrogol e.g. paediatric movocol, cosmocol, laxido
- Can add a stimulant laxative e.g. senna if above is inefficient
- Add lactulose or other softening laxative
What time of day should patients avoid taking bulk forming laxatives?
before bed as they increase peristalsis by increasing the volume of the stool but at night time peristalsis isn’t occuring
How should isphagula husk be taken?
Take 1 sachet BD
Mix the contents of 1 sachet with water and drink straight away
Take after meals, not at bed
How should methylcellulose be taken?
Take 3-6 (500mg) tablets BD with at least 300ml of water
Break in mouth before swallowing
How should macrogol be taken?
E.g movicol, laxido, cosmicol
1-3 sachets daily dissolved in 125ml of water
When should macrogols e.g. laxido, movicol be cautioned?
Are high in sodium
Caution in hypertension heart disease and renal patients
How should lactulose be taken?
Take 15-45ml a day
How should docusate be taken?
Up to 500mg daily
12-72 hours for tablets to have an effect and 15 minutes for suppositories
What is important regarding allergies and arachis oil enemas?
They contain nuts- avoid in nut allergy patients!
How should a patient use a suppository?
- Lie on the left side with the feet elevated
- Hold the suppository between the thumb and the middle finger
- Insert the blunt end of the suppository into the anus
- Lie still and hold it in for 10-15 minutes
How should a patient use an enema?
- Warm the enema in water
- Remove lid of nozzle
- Lie on left side, with knees bent up towards the chest
- Push the nozzle gently 7 cm into the anus and slowly squirt the contents into the anus
- try to hold the liquid in for 5 minutes
How should senna be taken?
Take 7.5mg-15mg daily
When is prucalopride used?
Only when treating chronic constipation
- used at 2mg OD (1mg if elderly)
- Review after 4 weeks, if no response, stop
What must happen before OTC laxatives can be given to children?
Children must be seen by a GP prior to being given laxatives over the counter.
The first line of laxative therapy for children are the macrogols e.g. paediatric laxido are POM, whereas the adult versions are p medicines.
What are the red flag symptoms of constipation?
- Bad pain on defecation
- Over the age of 40 with sudden changes in bowel habits
- 14+ days duration
- Associated fatigue
- Blood in stools
- Repeated failure of laxatives
- suspected laxative abuse
What OTC meds can be recommended for cramping associated with IBS?
Mebeverine 135mg tablets
Peppermint oil capsules
Buscopan- hyoscine butylbromide
