Australian Doctor 10th May issue 2024 | Page 31

HOW TO TREAT 31
ausdoc . com . au 10 MAY2024

HOW TO TREAT 31

Table 1 . Red flags for constipation Red flag Anorexia and unintentional weight loss
Rectal bleeding , stool mixed with blood or mucus
Anaemia or iron deficiency
Family history of inflammatory bowel disease or past colorectal cancer
Possible cause
Consider malignancy such as colorectal cancer
Consider colorectal cancer
Consider right-sided colon cancer Consider colorectal cancer / recurrence
Dr James Heilman / CC BY-SA 3.0 / bit . ly / 4449WN3
Fever , night sweats
Abdominal pain , abdominal swelling , vomiting
Acute change in stool frequency or stool volume
Consider constipation causing urinary retention and UTI ; infected diverticular disease
Consider bowel obstruction including surgical emergencies or faecal impaction
Consider acute surgical conditions
Box 3 . Medical conditions associated with constipation
DONE mnemonic :
• Dehydration and electrolyte disturbances ( hypercalcaemia , hypokalaemia ).
• Obstruction ( faecal impaction , colorectal cancer , diverticulosis , hernia , haemorrhoid ).
• Neurological conditions ( autonomic neuropathy , dementia , Parkinson ’ s disease , stroke , spinal cord injury ).
• Endocrine and metabolic conditions ( hypothyroidism , diabetes mellitus , uraemia ).
Also consider :
• Dietary , mobility and psychosocial factors .
• Low fibre and fluid intake .
• Immobility ( eg , bedridden ).
• Depression .
Figure 3 . Bowel obstruction .
Adapted from Chan ’ s Practical Geriatrics 4th edition with permission 25
mixed opioid agonist and noradrenaline reuptake inhibitor , as well as the combined preparation oxyco-
Box 4 . Drugs commonly associated with constipation
done / naloxone are newer opioids associated with less constipation . 35 Transdermal opioids ( fentanyl and buprenorphine ) are also less constipating . Rotating between hydrophilic opioids ( such as morphine , oxycodone or hydromorphone ) and lipophilic ones ( such as fentanyl , buprenorphine or methadone ) is commonly tried , but the practice lacks concrete supporting evidence . 35 Peripherally acting μ-receptor opioid antagonists are novel medications that have an increasing role in treating opioid-induced constipation ; an example of this is methylnaltrexone
ACID mnemonic :
• Analgesics : opiates , NSAIDs .
• Antacids : aluminium-containing antacids .
• Anticholinergic agents .
• Antidepressants .
• Antipsychotics .
• Anticonvulsants .
• Calcium-channel antagonists .
• Calcium supplements .
• Iron supplements .
• Dopamine agonists , levodopa .
• Diuretics .
Adapted from Chan ’ s Practical Geriatrics 4th edition with permission 25
Figure 4 . Taking a medication history is crucial .
bromide , which is TGA approved . 36
Lifestyle and dietary
Adequate fluids , and dietary and
Bowel retraining
Bowel retraining includes advising
patients to implement a regular daily
constipation . 32 This approach entails instructing those with the cognitive capacity to relax instead of tens-
meet the increased fluid requirements of bulk-forming laxatives . 37 , 45 The consensus statement also recommended
and may result in bloating and flatulence . Other osmotic laxatives are not broken down by gut bacteria but
lifestyle modifications such as
routine that involves opening their
ing their pelvic floor and abdominal
that a suitable alternative to these
are more likely to cause dehydra-
active lifestyle ( avoidance of sedentary lifestyle ) can be trialled , although these are not always feasible in older patients . Guidelines recommend trialling these before
32 , 37 pharmacological interventions . Adequate hydration is impor-
bowels either within 30 minutes after meals to take advantage of the gastrocolic reflex or early in the morning when colonic activity is peaking . 37 , 40 It is also important to educate patients about promptly responding to the urge to defecate , refraining from pro-
muscles during straining , aided by visual or auditory cues that offer feedback to the patient . A Cochrane review found that 40-100 % of patients report improvement with biofeedback ; however , the evidence supporting this was of low quality . 42
for softening the stool is docusate sodium . 38 If stools are soft yet difficult to pass , a stimulant laxative , suppository or enema should be considered .
OSMOTIC These agents include lactulose , sorb-
tion . Polyethylene glycol is overall superior to lactulose in increasing stool frequency , relieving abdominal pain and preventing reliance on additional products . 46 There is insufficient research to establish the effectiveness and safety of magne-
tant but the recommended daily
longed pushing , and ensuring con-
Consider the cognitive func-
itol , polyethylene glycol ( macro-
sium salts , specifically in older indi-
fluid intake may need to be bal-
venient access to the toilet . 16
tion , physical status and degree of
gol ), various magnesium salts and
viduals . It is therefore not advisable
anced against conditions that require
For physically capable patients ,
co-operation the patient is capable
sodium phosphate . They are osmot-
to use these for prolonged periods
restriction , for example , cardiac or
appropriate defecation posture can
of when recommending or imple-
ically active and obligate diffusion
because of concerns about potential
renal failure , so the recommended
optimise defecation mechanics . This
menting behavioural management
of water into the lumen to maintain
magnesium toxicity . Note that mag-
volume may vary . If immobility is
involves incorporating a footstool
therapies . 16
isotonicity with plasma . Lactulose is
nesium salts are contraindicated in
a contributing factor , patients can be encouraged to mobilise if able . A diet rich in fibre ( unprocessed grains ,
to ensure the knees are elevated higher than the hips , leaning forward and placing the elbows on the
Laxatives
Laxatives are used as second-line
a synthetic disaccharide commonly used in older persons . Sorbitol is an effective and cheaper alternative .
older patients with renal failure . 47
BULK-FORMING
fruits and vegetables , see figure 9 ) is encouraged to help alleviate constipation . 38 The side effects of bloating , cramping and flatulence associated with a high-fibre diet can be avoided by titrating dietary fibre slowly
knees , bulging out the abdomen , and straightening the spine . 41
Biofeedback
Biofeedback is a viable alternative , particularly for older indi-
treatment and are administered on a prn basis . Educate the patient and caregiver on proper use , as laxative dependence and abuse are common among older persons . 43 , 44 Osmotic laxatives are preferred over bulk-forming
Polyethylene glycol or macrogol is a biologically inert , non-absorbable osmotic laxative . Its powder preparation is mixed with sodium chloride , potassium chloride and sodium bicarbonate to be dissolved in solu-
Natural fibre ( psyllium , bran ), semi-synthetic fibre ( methyl cellulose ) and synthetic fibre ( polycarbophil ) hold additional water in the stool and avoid digestion and absorption in the small intestine , thus increas-
upwards to the recommended daily
viduals experiencing dyssynergic
laxatives in older patients because of
tion for use . Lactulose and sorbi-
ing stool frequency , stool weight and
intake of 20-35g per day . 39
defecation rather than slow-transit
the inability of some older people to
tol are fermented by gut bacteria
reducing colon transit time . Patients