Australian Doctor 10th May issue 2024 | Page 32

can experience bloating and excess

as clinical syndromes is still a mat-

flatulence . Advise patients to take

ter of debate , and discontinuation of

additional fluids to avoid the potential drug-induced complication of intestinal obstruction . 48 Older individuals at risk of dehydration including those

stimulant laxatives seems to reverse these alterations . 52 , 53 Additionally , there are currently no reliable data establishing a connection between

with immobility , cognitive impairment

chronic use of stimulant laxatives

or swallowing issues should avoid

and colorectal cancer . While the

bulk-forming laxatives . Also avoid

chronic use of these laxatives may

bulk-forming laxatives in the setting of

result in a benign condition called

faecal impaction and opioid-induced constipation . 49 Opioids hinder the peristalsis needed to propel the increased

melanosis coli ( see figure 10 ), characterised by darkened colonic mucosa , it holds no pathological signifi-

bulk , which aggravates abdominal

cance . However , daily ingestion of

pain and can ultimately contribute to

these laxatives can potentially lead

bowel obstruction . 49

to complications such as hypokal-

There is more evidence for the effectiveness of psyllium than bran in treating constipation in older people . 50 A small number of studies in older adults demonstrated equiva-

aemia , protein-losing enteropathy , and salt depletion . 54 Overall , caution should be exercised when considering the chronic use of stimulant laxatives , especially in older individuals ,

lent effectiveness of methyl cellulose

as long-term safety evidence in this

and polycarbophil to psyllium . 51

population is still lacking . 37

STIMULANTS

STOOL SOFTENERS AND

These agents include diphenylmeth-

LUBRICANTS

ane derivatives ( phenolphthalein

Stool softeners ( docusate sodium )

and bisacodyl ) as well as anthraqui-

and lubricants ( mineral oils ) emul-

nones ( senna and cascara ). They

sify stools and provide lubrication

directly act on the mucosa by stim-

for the passage of faecal pellets .

ulating the myenteric plexus and

They may be given orally or as reten-

altering water and electrolyte secre-

tion enema . Although stool softeners

tion . The onset of action varies

possess a more desirable side effect

from 10 minutes to 12 hours . There is conflicting evidence regarding the long-term safety of stimulant laxatives . Studies from the 1960s- 70s suggest the rare possibility of enteric neuropathies with chronic

profile , they are less effective than other laxatives . 3 Aspiration of mineral oil can cause lipoid pneumonia , while long-term use can cause malabsorption of fat-soluble vitamins and foreign body reactions in

Figure 5 . Abdominal X-ray showing faecal loading .

use ; however , recent studies with

the intestinal mucosa and regional

more advanced technology have

lymph nodes . 55

enemas can lead to disturbances in

can cause harm to the rectal mucosa ,

OTHER

not confirmed these findings . Long-

fluid and electrolyte balance , as well

while regular use of phosphate ene-

In laxative-refractory patients with

term utilisation of stimulant laxatives has been linked to a condition known as ‘ cathartic colon ’, charac-

ENEMAS AND SUPPOSITORIES Enemas and suppositories can be used for faecal impaction and as an

as irritation of the rectal mucosa . Improper administration techniques may result in mechanical injury . It

mas may result in hyperphosphataemia . 55 As a safer alternative , warm tap water can be used , as can glyc-

chronic constipation , novel pro-secretary agents which promote electrolyte efflux and diffusion of water

terised by the presence of luminal dilation and loss of haustration as observed in barium enema examina-

alternative in individuals who cannot tolerate oral laxatives . 47 Enemas induce defecation by causing

is important to note that rectal perforation can occur , particularly if manual disimpaction has not been

erin suppositories . Patients with intractable constipation may require referral for surgical treatment . The

into gut lumen have been developed but evidence for use in older people is limited . Prucalopride is a selective

tions . However , the extent to which

rectal distension and flushing out

performed beforehand . Frequent

usual approach is subtotal colectomy

agonist of serotonin 5-HT4 which

these radiological changes manifest

faecal matter . However , the use of

use of phosphate and soap enemas

with ileorectal anastomosis . 56

is available in Australia , however it