For more than 17 years, James Lavers was assured by several doctors that the bloating and pain he experienced on and off from his early 20s was irritable bowel syndrome (IBS). His story is far from unique.
Gut complaints are extremely common, accounting for one in five GP consultations and millions of over-the counter sales of gastric relief products, for everything from acid reflux and bloating to diarrhoea. And IBS, thought to affect up to 14 million people in the UK, is a very common diagnosis.
Yet some experts believe that doctors are too ready to suggest this is the cause of patients’ symptoms. They argue that there are other conditions, some previously dismissed as ‘hokum’ (see box below), that could lie at the root of the problem — and, ironically, the very treatment patients are given to ease their gut symptoms could make these worse.
It seems that this was the case for James, 36, a property management consultant. From his early 20s, he suffered from episodes of bloating and painful cramps every few weeks. Once, in 2003, he went to A&E because the pain was so bad, but doctors said it was trapped wind.
For more than 17 years, James Lavers was assured by several doctors that the bloating and pain he experienced on and off from his early 20s was irritable bowel syndrome
‘Over the years I must have seen four different GPs and as many gastroenterologists, on the NHS and privately, and they all seemed to agree it was IBS,’ says James, who lives in South London with his wife Sally, 34, an accountant, and eight-month-old daughter Esme. But the treatments, such as antispasmodic drugs for wind and bloating, made no difference.
‘The symptoms really impacted my everyday life, affecting my social life and wellbeing,’ he says. ‘If I had a night out eating and drinking, I’d suffer for days afterwards.’
James paid to see nutritionists — five in 15 years — who advised him variously to take probiotics, digestive enzymes, vitamin and mineral supplements.
‘Sometimes they did blood tests or stool tests and said I had deficiencies,’ says James. ‘These supplements could cost up to £300 for a couple of months’ supply, but I was never totally convinced about them.
James paid to see nutritionists — five in 15 years — who advised him variously to take probiotics, digestive enzymes, vitamin and mineral supplements
‘I was also told I might have food intolerances, so at various points I tried excluding wheat/gluten and dairy, and then FODMAPs.’ (These are sugars found in foods such as onions, garlic and some fruits that ferment in the small intestine and have been shown to cause bloating and diarrhoea in some people.)
Compounding the problem, in his mid-20s James also began suffering from belching, heartburn and acid reflux that left his throat ‘sore and raw’.
‘It was ruining my life — I’d sometimes feel so sick I couldn’t eat for days,’ he says. He saw a gastroenterologist privately, and after a gastroscopy (where a camera is passed down the throat in a thin, narrow tube) he was diagnosed with acid reflux and prescribed proton-pump inhibitor (PPI) drugs to suppress his stomach acid production.
While the acid reflux symptoms improved, he was still living with the bloating, cramps and belching, with ‘a really bad attack’ every six months or so for the next decade. Then, 18 months ago, he went to a private clinic specialising in gut complaints on the recommendation of a friend.
The consultant ran a number of tests, including a simple breath test for small intestinal bacterial overgrowth (SIBO).
This condition occurs when there is too much bacteria in the small intestine which ferment, producing gases such as hydrogen and methane and causing symptoms in the upper end of the digestive tract, including belching and bloating, as well as heartburn-type symptoms or a feeling of a lump in the throat.
If the bacteria overgrow in the lower end of the small intestine, this can cause lower bowel symptoms, such as cramps, bloating, changes in bowel habit, diarrhoea and loose stools. In other words, symptoms similar to those of IBS.
Research suggests that up to two-thirds of IBS cases may be caused by this bacteria overgrowth. A study published online in the medical journal Surgical Endoscopy found that two-thirds of 104 patients referred with regurgitation symptoms (i.e. acid and reflux) that had proved resistant to treatment, also had SIBO.
Although the condition was first identified more than 50 years ago, it has been regarded with scepticism by some gastroenterologists. But that has recently changed — for instance, the British Society of Gastroenterology’s guidelines on the management of chronic diarrhoea, published in 2019, recommend SIBO should be ‘routinely considered as a possible cause of GI [gastrointestinal] symptoms’.
Even though it’s widely accepted now that some patients with IBS could have SIBO, awareness of the condition generally is still poor among GPs and some gastroenterologists, so people are rarely checked for it, says Nick Boyle, a reflux surgeon based in Tunbridge Wells, who led the latest research.
As a result, patients can have symptoms for years and be told they have IBS or reflux and that they have to live with it, when actually they have SIBO, which is treatable and curable, says Mr Boyle. This contrasts with IBS, for which there is no cure — although antispasmodics, laxatives and other treatments can help manage symptoms.
One of the most common causes of the problem, suggests Mr Boyle, are PPI drugs prescribed to treat heartburn and acid reflux.
Normally, the small intestine doesn’t have many bacteria because food is sterilised in the stomach by acid and pancreatic enzymes, but this process can be disrupted by various factors — including medication. However, because these drugs suppress stomach acid, ‘food and bacteria are not killed off, and can reach the small intestine’, says Mr Boyle, who worked as an NHS GI surgeon for 20 years and is medical director of the RefluxUK group of private gut clinics.
Proton-pump inhibitor drugs are some of the most widely prescribed in the country. One of them, omeprazole, was the third most commonly prescribed drug in 2019, with 31.5 million items dispensed. Another, lansoprazole, came in sixth, at 26.7 million.
Several studies have found an association between these drugs and bacterial overgrowth, including a review of 19 studies with 7,000 patients published in the journal Gastroenterology in 2018, which confirmed a three-fold increase in risk of the problem with PPI use.
Experts believe doctors are too ready to suggest IBS as the cause of symptoms. Stock image
Another study, in the European Journal of Clinical Investigation in 2010, found 26 per cent of patients taking the drugs for oesophagitis (inflammation of the lining of the oesophagus owing to acid reflux) had developed SIBO after eight weeks. All had tested negative for the condition before taking PPIs.
And a 2019 study of 1,500 patients, published in the Mexican Journal of Gastroenterology, found that 92 per cent of those prescribed these drugs for gastric reflux and stomach ulcers reported suffering from IBS-type symptoms, with 82 per cent suffering bloating and 63 per cent complaining of abdominal pain.
For 41 per cent of patients these were new symptoms — ones they had not had before taking the stomach acid pills.
The same study found that those who were then treated with the antibiotic rifaximin (a drug recommended for SIBO) reported the greatest improvement in symptoms compared with those taking other drugs, such as antispasmodics.
Mr Boyle emphasises that PPIs are a good treatment ‘if used in the right people to treat the right conditions’, and that they are effective in preventing cancer in people with Barrett’s oesophagus (a pre-cancerous condition associated with severe reflux).
Antibiotics may also trigger bacterial overgrowth, as these — like the stomach-acid suppressants — can alter the balance of the gut microbiome, the colony of microorganisms in the gut, allowing harmful bacteria to overgrow in the small intestine.
Because SIBO symptoms overlap with those of more serious conditions, such as inflammatory bowel disease, coeliac disease and cancer, these need to be ruled out, says Mr Boyle.
‘But SIBO can be diagnosed with a simple breath test — available on the NHS though not widely,’ he says. ‘These can be sent out as kits that people can do at home.’ The tests involve swallowing a sugary syrup (which contains lactulose, usually used as a laxative) and breathing into bottles over a couple of hours. These samples are sent to the lab to check the levels of hydrogen or methane. High levels indicate that you may have the condition.
After the diagnosis is confirmed, treatment includes antibiotics. A study in the journal Gastroenterology in 2013 found that rifaximin can improve SIBO symptoms in up to 64 per cent of cases, but the drug is expensive (from around £110 for a ten-day course), so is not always widely available and is usually prescribed only by specialists.
The same study found that cheaper, broad-spectrum antibiotics, such as ciprofloxacin, metronidazole and tetracycline, were effective in 41 per cent of cases and can be tried instead.
Peter Whorwell, a professor of medicine at Manchester University, says it’s a paradox that antibiotics can cause SIBO as well as treat it.
‘The idea is that if you’ve had a long course of antibiotics and they’ve killed off certain bacteria, a course of different antibiotics can then be used to kill off bacteria that have overgrown, especially in the small intestine where they shouldn’t be in the first place,’ he says.
Trying a low-FODMAP diet for four to six weeks under the supervision of a dietitian after a course of antibiotics may also help, says Mr Boyle. ‘Removing the foods that bacteria feed on effectively starves them out.’
Some people need surgery for reflux so they no longer have to take PPIs — as happened with James, who had been taking the pills for seven years.
In February last year, he had Linx surgery, where a bracelet of magnetic beads is placed around the oesophagus to reinforce the weakened valve at the bottom and prevent the acid reflux. His gut symptoms improved and he no longer takes acid reflux drugs — he is also going to start a two-week course of rifaximin to tackle the cramps and bloating in his lower gut.
‘I’m not completely cured but, after almost 20 years of looking for answers, where I am now is so much better than being told it’s ‘just’ IBS or being put on PPIs, which can make the symptoms worse,’ he says.
There is still controversy about how common SIBO is, how best to test for it and treat it. There are also questions over the link to PPIs, with studies, including one in the journal Gastroenterology in 2016, showing that patients with IBS had SIBO even when they didn’t take acid-suppressant pills.
Dr Simon Smale, a consultant gastroenterologist at Manchester University Hospital, says that the bacterial overgrowth is an ‘unusual’ symptom of taking PPIs.
Professor Whorwell concurs, saying that around one in ten of the IBS patients he tests for SIBO has a positive result. ‘I don’t dispute it exists — it definitely does — but what I can’t decide on is whether SIBO is the cause or an effect of the IBS,’ he says.
He has prescribed rifaximin to patients and, while some ‘certainly do improve, unfortunately their symptoms do tend to come back again’.
Dr Smale adds: ‘There are also issues with the breath test. It is not particularly specific and there are lots of variables that can affect the outcome of the tests, including not fasting for long enough before drinking the lactulose.’
He suggests that the majority of people who see their GP about bloating will not have SIBO. ‘The most common cause of bloating is simply eating too much,’ he says.