New guidelines set out the best course of attack for treating constipation in adults.
Gastroenterologists have recommended magnesium oxide and senna for chronic idiopathic constipation for the first time in new guidelines.
The American Gastroenterological Association and the American College of Gastroenterology also made strong recommendations for the osmotic laxative polyethylene glycol (Macrogol, Movicol) and the stimulant laxatives bisacodyl (Dulcolax) and sodium picosulfate (Dulcolax SP drops).
In their review of the latest evidence for over the counter and prescription medication, the experts also gave conditional recommendations for fibre supplements as a first-line treatment, lactulose (Actilax), senna (Senokot) and magnesium oxide.
In their recommendation for fibre supplementation, the authors noted that only psyllium appeared to be effective and said there was limited and uncertain data on bran and inulin.
The authors said lactulose could be used for patients who were intolerant or had not responded to over the counter therapies.
Bisacodyl and sodium picosulfate were recommended short term or as “rescue therapy”.
Australian gastroenterologist Associate Professor Rebecca Burgell said the guidelines provided a good systematic overview of the available evidence.
“It gives medical practitioners confidence with the therapies that they’re recommending,” said the head of the functional GI disorders service at Alfred Health and Monash University.
Professor Burgell recommended that patients over 40 with sudden changes in bowel symptoms be referred to a gastroenterologist for a colonoscopy and suggested that women have a pelvic ultrasound to check for ovarian pathology.
“But … if there are no red flags, no bleeding, no weight loss, no masses on examination, no anaemia, no suggestion of any inflammation in either blood tests or stool tests, a GP can be reassured if it’s been a long-standing problem that they probably don’t need further investigation.”
Professor Burgell said a sedentary lifestyle was a key cause of constipation, but several medications could also be to blame.
The side-effects of painkillers were well known, but cardiovascular medications, anti-psychotics and diabetic medications commonly contributed to constipation.
Professor Burgell said calcium channel blockers commonly caused constipation and the effects could be offset by increasing fibre and taking an osmotic laxative.
Patients may “accumulate” medications over the years and it was worth doing a comprehensive review of medication if a patient has bowel symptoms, she said.
“Unless the symptoms are severe, the risk benefit was probably still in favour of continuing, but you may need to offset the effects of those medications.
“With constipation, a good first port of call is to review the medications that they’re on and see if there is anything that’s contributing, and then review their dietary intake. Are they getting enough fibre? Are they getting enough fluid? Going back to those first principles can be really effective.
“If we can avoid adding medications to treat the side effects of medications, it’s always preferable, but we have to balance that up against, say, someone’s cardiovascular risk, which obviously can be life threatening. It’s all a balance.”
Professor Burgell said laxatives such as the PEG-based laxatives, the saline osmotic laxatives, magnesium-based laxatives, lactulose and stimulant laxatives such bisacodyl or senna were safe to use every day.
“Laxatives at standard doses are safe to take each day.”
Professor Burgell said there was no evidence that taking laxatives at standard doses damaged the bowel or caused irreversible harm or nerve damage.
“When a patient that has chronic constipation and needs a stimulant laxative every day, that is not the end of the world. But if that patient started increasing and increasing the doses, having loose stools, having other complications, that’s when it becomes a problem.”
“The key thing is to make sure they’re not being abused for other reasons.
“It is not uncommon for patients to become obsessed with their bowels to overuse laxatives, and there’s multiple different reasons why that may be. And that’s the more important thing to address rather than putting the fear of God into the patient that they’re going to damage the bowel, because that’s not the case.”
“If people are abusing laxatives and using really high doses, the colon stops working, but you can wind those back quite successfully and you will get the function of a bowel coming back.”
Professor Burgell said there were no official Australian guidelines regarding constipation apart from the Therapeutic Guidelines. The online program at IBS4GPs also provided a useful treatment algorithm and referral information about irritable bowel syndrome for GPs, she said.
