Constipation Flashcards
Define constipation
i) A change from your normal bowel habit – important to elicit what is normal
ii) A symptom not a condition
What are the most common causes?
i) Lack of fibre and fluid
ii) Lack of physical activity
iii) Drugs – esp opiates, iron supplements, anticholinergics, CaBs, antacids with aluminium, cytotoxics
What are some other system based causes?
Neurological - MS, Parkinson’s, CVA, spinal cord lesion
Metabolic - Pregnancy, DM, hypercalcaemia, hypothyroidism
GI - IBS, colon Ca, diverticular disease, obstruction, Crohn’s , haemorrhoids
Psychiatric - depression, psychosocial factors – societal expectation
How do you investigate constipation?
Patient will often tell you and examination is not required
If treatment not working or patient risky i.e. showing neruo or Ca signs
- Check perineum and PR – ?impaired sensation, rectal mass, prolapse etc
- Vaginal/rectal examination if pelvic floor defect is suspected cause
- Radio opaque markers on XR
What are some pre-pharmacological methods of managing constipation?
Treat underlying cause
Education on what is normal and how to spot when you’re not passing normally
Increase dietary fibre (20-30g) and water intake (6-8 glasses)
Lose weight
Exercise more
Fruits with high sorbitol content are good – apples, apricots, grapes, peaches, pears, plums, raspberries, strawberries + whole grains
and vegetables
What is the treatment pathway for acute and chronic, non-opioid constipation?
Lifestyle advice
1st line - offer bulk forming laxative i.e. fibogel (ispaghula husk); up to 72hrs between administration and onset of action, must maintain fluid intake
If ineffective – osmotic laxative i.e. macrogol; 2nd line lactulose
If still difficult to pass – add stimulant laxative i.e. bisacodyl, senna
What other options are available?
Faecal softeners:
- Glycerol suppositories
- Given for hard stool (often with bisacodyl suppository too)
Enema:
- Last resort, good for impaction
– With arachis/peanut oil can also soften stools
- Sodium phosphate and docusate are alternatives
– May need a number of repeats
How do you treat opioid constipation?
Don’t prescribe bulk-forming
Offer osmotic + stimulant laxatives
How do the different types of laxatives work?
Bulk-forming - absorbs liquid in the small and large intestines creating a liquid like stool that’s softer and easier to pass; work like a dietary fibre
Osmotic - draws fluid out of intersitita into colonic lumen or retention of fluid they were administered with
Stimulant - increase intestinal motility
What are some other important things to note about laxative prescription?
Don’t become reliant as can permanently affect bowel function
Advise person to gradually reduce and stop once soft formed stools are being produced without straining at least 3x/wk
