Constipation Flashcards
Define constipation
Unsatisfactory defaecation due to infrequent stools, difficult stool passage or seeming incomplete defaecation.
Typically passing less than three stools a week
Most common in women, elderly and pregnancy.
What type of constipation should be further investigated?
New onset
Esp in 50yrs+ with anaemia, abdo pain, weight loss, overt/occult blood - due to risk of malignancy.
If accompanied with vomiting/absolute/ suspect BO.
What lifestyle advice can help treat constipation?
In dietary fibre - should be done gradually to avoid flatulence and bloating.
Foods high in fibre and sorbitol - such as prunes, peaches or fruit juices.
Increased fluid intake
Regular exercise
Toiler routine changes - ensures goes when feels the need, takes time to ensure defecation is complete
What electrolyte abnormality is common in laxative abuse?
Hypokalemia.
What are the different types of laxatives?
Bulk-forming - inc stool weight and soften it (fibrogel)
Stimulant - stimulate nerves in colon
Faecal softeners - inc water and fat in stool
Osmotic laxatives - draw water into colon
What are the different stool types on a Bristol Stool Chart?
Give an overview of bulk-forming laxatives
Examples – fybogel
Mechanism – indigestable hydrophilic colloids – absorb water and swell – increasing faecal mass and GI wall distention – stimulate peristalsis
Usually takes 2-3days to work, often used in IBS, Diverticulitis and safe in elderly
Side effects = bloating and flatulence, interfere with warfarin absorption,
Cautions = needs to be taken with fluids or can cause a blockage – avoid in fluid restricted patients. Use with care if risk of obstruction such as strictures or many adhesions
Give an overview of osmotic laxatives
Example – lactulose, milk of magneisum, glycerin, macrogol
Mechanism – poorly absorbable and hydrophilic -> keep water in the lumen, fecal matter not as hard, easier to pass. Can work in as fast as 1hr
Side effects – high risk of dehydration and electrolyte imbalances in patients with renal failure (cautious in elderly). Cramping and bloating.
Give an overview of stool softners
docusate
Mechanims – allows water and lipid to penetrate stools -> softer and easier to pass.
Usually take longer than other laxatives, used in patients who should not strain such as post surgical, post natal, hemorrhoids, HTN or hernias.
Give an overview of stimulant laxatives
example = senna
Cause direct stimulation of ENS and colonic secretions. Takes 8-24hrs to work
Side effects – accumulation of melanin causes urine and bowel discoloration.
What are some symptoms of constipation?
Fewer than three bowel movements a week
Difficult time passing stools
Lumpy or hard stools
A feeling of being blocker or of not having fully emptied your bowels.
Elderly may also present with constipation
What are some medical conditions that can cause constipation?
Neurological - stroke, Parkinsons disease, spinal cord injury
Diabetes
Tumours or blockages
Pelvic floor disorders, Irritable bowel syndrome.
Alzheimers disease - not causative but can increase the risk
Medications - Parksinsons disease drugs, iron supplements, anaesthesia, opiods
At what point is constipation considered chronic?
3 months or more
What is important to ask about the patients bowel motions if they are constipated?
How often? normal?
Consitency?
Colour?
Bloor or mucous?
Pain or straining?
Feeling incomplete emptying of stools?
Duration
What associated symptoms need to be considered in a patient with constipation?
Abdo pain
Abdo distention or bloating
Nausea or vomiting - faeculent or bilious
Loss of appetite
Overflow diarrhoea
Urinary retention
Any confusion or derlirium
What are the red flags for constipation?
Colorectal cancer - sudden change in bowel habit, bleeding, weight loss, fatigue, malaise, nigh sweats, iron deficiency anaemia
Ovarian cancer - change in bowel habit, bloating, early satiety, pelvic/abdopain, urinary urgency or frequency, women over 50yrs.
BO - constipation, vomiting, bloating
What are the signs of constipation of abdominal examination?
Distention
Abdominal massess
Liver enlargement
Tendernesss
Increased/decreased bowel sounds
What are the signs of constipation on perineal inspection?
Skin tags
Fissures
Prolapse
Anal warts
Perianal ulceration
What are the signs of constipation on digital rectal examination?
Inner haemorrhoids
Sphinter tone
Tenderness
Obstruction/stenosis
Impacted faeces
Completed absence of stool
Tumour masses
Blood
What are the physical risk factors for constipation?
Older age
Female sex
Immobility
Dehydration
Seating position when passing bowel motion
Medications - opioids, oral iron
What are some social risk factors for constipation?
Low fibre diet
Low calorie intake
Low water intake
Limited exercise
Family history of constipation
Socio-economic deprivation
Ignoring the urge to go to the toilet
What are some psychological risk factors for constipation?
Anxiety/depression
Eating disorders
Somatization disorders
History of sexual abuse.
What is meant by secondary constipation?
Medical conditions that can cause constipation
What are some GI tract conditions that can lead to secondary constipation?
IBD
Colorectal cancer
Rectal prolapse
Haemorrhoids
Anal fissures and strictures
Pelvic floor damage
What are some endocrine and metabolic conditions that can cause constipation?
Diabetes - autonomic neuropathy
Hypothyroidism
Hypercalcaemia
Hyperparathyroidism
Hypokalaemia
Hypermagnesaemia
What are some neurological conditions that can cause constipation?
cerebrovascular disease e.g stroke
MS
Parkinsons disease
Autonomc neuropathy
Hirchsprungs disease
What type of laxatives should be given for opioid induced constipation?
Osmotic (laxido)
Stimulant (Senna)
What laxatives tend to be used for acute and chronic constipation?
1st line - bulk forming (isphagula husk)
2nd - if hard stool and difficult to pass add/switch to osmotic e.g laxido
3rd - change to diff type of osmotic - lactulose
2nd if soft but difficult to pass - stimulant e.g senna
3rd prokinetic e.g prucalopride
What laxatives should be used for faecal impaction?
Complication of chronic constipation (Faeces merges unable to pass)
1st for hard stools - osmotic e.g laxido
1st for soft stool - stimulant e.g senna
2nd - suppositories or mini enema
3rd - enema phosphate
What surgical interventions may be used for constipation?
Manual evacuation
In severe cases, colectomy +/- stoma formation e.g subtotal colectomy with ileorectal anastamosis
