Q&A: DR LISA DAS
Gastroenterologist at The London Clinic on irritable bowel syndrome, a common but widely misunderstood condition
INTERVIEW: Viel Richardson
PORTRAIT: Alice Mann
What is irritable bowel syndrome (IBS)?
IBS is one of the most common conditions that we see in gastroenterology clinics, occurring in about 50 per cent of patients. It is essentially abdominal pain related to disordered bowel habits. That can be either a change in the frequency of going to the toilet or in the form of the stool when you do. But there can be other symptoms, too.
Why is it called a syndrome?
A syndrome is a collection of associated symptoms, as opposed to a specific disease process. It means that there is no single underlying mechanism causing the problem and is what we call ‘multifactorial’. So technically there is no ‘cure’ as there is no disease mechanism to fight.
Is there a clinical definition of IBS?
There is a group of experts called the Rome Foundation, which focuses on improving treatments for gastrointestinal disorders. They have been working on IBS since the 1980s and the most recent definition from 2016 is called the Rome IV criteria. It defines IBS as “any abdominal pain that is associated with a change of the bowel habit, has been present for at least one day a week for the last three months, and started at least six months ago”. There may be a range of other symptoms associated with IBS—these can include nausea, headaches, migraines, fatigue, joint pain and skin rash. There are many factors underlying IBS, but the exciting thing is that we are learning more about it all the time.
So, it is not purely a gut and intestinal problem.
We are beginning to realise that it is not. In fact Rome IV addresses that. We increasingly realise that we are dealing with disorders in the relationship between the gut and the brain—what we call the gut-brain axis. The new nomenclature is ‘disordered gut brain interaction’.
How do patients generally present?
Everybody can have different symptoms. One person will have abdominal pain, one will have severe bloating, another could present with constipation or diarrhoea. They may suddenly develop this urgent need to get to the toilet, especially after meals. Also, the patient doesn’t have to have one major symptom, but can have several that are all equally distressing.
What is actually happening during IBS?
We know it is related to several mechanisms: abnormal gut motility (which is the way the gut moves and pushes food along), as well as abnormally heightened sensation in the gut, or abnormal immune mechanisms, occasionally triggered by a localised infection in the gut. There is also this new understanding of how the gut-brain axis impacts on the syndrome. We are learning much more as we investigate that further, which should help develop new modes of treatment, and further research is ongoing.
Has there been a change in approach in your time as a gastroenterologist?
The biggest change is that we now take IBS seriously. There is a small subset of clinicians who don’t, but the majority of us positively recognise IBS as a clinical diagnosis. There is now a general acceptance that by targeting the symptoms we can make a huge difference to IBS sufferers.
Are certain people more at risk?
Females are 1.7 times more likely to get IBS. People suffering from anxiety or depression have a heightened risk. About 20 per cent of sufferers will develop it after a gut infection. It can also appear after a course of antibiotics. In this case, the underlying mechanism is thought to be connected to the ‘gut microbiome’, a collection of bacteria living in the gut. We need the gut microbiome to stay healthy, and this is all too easily disrupted by antibiotics. Also, if you look at children who have had trauma in their lives, they are far more likely to develop IBS later in life.
So your mental state can impact on IBS?
Anxiety and depression can be precursors of IBS and can also cause worsening IBS symptoms, which are themselves distressing—you can find yourself with a vicious cycle, spiralling downwards.
If untreated, can it lead to something more serious?
The simple answer is no. IBS patients have been studied over 30 years and there is no evidence of it developing onto something more serious.
What would you say are the most common misunderstandings?
A major, and dangerous, misunderstanding is that bleeding from the rectum when you pass a stool is a symptom of IBS. This is absolutely false. Bleeding is not a symptom of IBS—if you see blood, this has to be investigated, because it can be a symptom of or precursor to some much more serious diseases.
Are there other symptoms that don’t fit with IBS?
Yes, there are several ‘alarm features’ that suggest we may not be just dealing with IBS. These include sudden weight loss, or a family history of bowel cancer, colitis or Crohn’s disease, or coeliac disease. Also, symptoms that wake people up in the middle of the night are not typical of IBS. It is incredibly important if you have been living with a series of symptoms for some time that you make sure to highlight problems that could indicate something far more serious.
After diagnosis, what is the next step?
You have to gain the patient’s confidence; reassurance is so important. As you develop a self-management plan, the patient begins to get a better awareness of their body. There are lightbulb moments where the patient realises what has been happening and you can see them physically relax. They stop worrying and start thinking. I have seen the simple act of understanding make a huge difference to patients. Suddenly, they are able to manage their condition in a way they couldn’t before. There may be some dietary changes needed, and therapies such as cognitive behavioural therapy (CBT) can play a part. This is about taking a multi-modality approach.
Are there medications you can use?
There is no miracle drug for IBS, so it is about managing the symptoms. We do have medications that target specific symptoms. One is a new guanylate cyclase medication called Constella (linaclotide), which works on receptors in the lining of the bowel. This increases fluid secretion into the bowel, which can help with bowel movements. It also increases the contractions which push things through the bowel, and additionally, it works on the nerves to reduce abdominal pain. In those people for whom it is appropriate, it can be a life-changing drug.
There are also treatments that have arisen by re-visiting the literature. One area is ‘bile acid malabsorption’, which can cause chronic diarrhoea. Around a third of IBS patients have bile acid malabsorption, and there is existing treatment for that. Suddenly a third of your patients can be treated for a debilitating symptom that impacts on everyday life.
How does nutrition fit in?
This is of course incredibly important, but there is a great deal of confusion. Some people come in eating almost nothing, because they have restricted their diet so much. I can often tell them that they can return to a relatively normal diet, which is a revelation. Suddenly they can go out with friends and enjoy themselves again. You hear a lot about the low FODMAP diet, which can be very effective if properly followed with a dietician. But it can also be complex and difficult to understand, and I see many people who have tried it and given up.
Can there be a hereditary aspect?
At present, IBS is not thought to be hereditary. There is familial clustering, however, which may be due to learnt social behaviour or environmental factors. On the gene side of things, there is no evidence of hereditary passing-on of IBS. It is, though, a current area of research.
What drives your interest in IBS?
The fact that it is so common and can be so hugely detrimental to people’s quality of life. World-wide the prevalence of IBS is 12-15 per cent. If you look at the questionnaires returned by IBS patients, they are a long way below average on their quality of life scores, more in keeping with those with diabetes. These sufferers can also have lower productivity and higher absenteeism. With the right approach, we could help a great many of them.
What would you say to all those people with IBS, currently suffering in silence?
I would say that if you have tried to get help in the past and have not been believed or well-managed, please have another try, because things are very different now. IBS is something that can seriously impact on some lives. There is no cure as it is not a disease process, but management can be much, much better. Many people have been frustrated with visiting multiple physicians. Much has changed, and we are learning so much more about IBS. It is always worth another try, especially if symptoms are seriously affecting your work, your life and your relationships.