I was never diagnosed with Irritable Bowel Syndrome (IBS) but sometimes I feel like I now have it. I know many others feel the same way. But when I look at the alternatives, I can’t help thinking it’s a small price to pay given that one of them might be a slow degrading quality of life until shuffling off this mortal coil. If I had the choice again, I would still take the surgery.
Before the article continues, let me be clear – I’m not suggesting this is a potential treatment for NET patients with post abdominal surgery side effects or side effects of any other treatment, nor am I suggesting it’s a potential treatment for those with carcinoid syndrome diarrhea. I publish it because there is a connection to serotonin and it may be a useful read for the more curious amongst us. In fact, since publishing I’ve been contacted by several people telling me they are aware of the drug having been treated with it for nausea.
I once wrote about IBS in an article entitled “Were you irritated by your misdiagnosis” (click the link to read). This was written after I completed an online IBS course. I wrote the article in a balanced way in an effort to explain why many patients are misdiagnosed with IBS in the lead up to the correct diagnosis some time later. This is an issue with other conditions, not just NETs. It was also designed to capture IBS readers and offer them a chance to review their diagnosis to ensure there wasn’t anything else they might try to double-check (markers and scans mainly).
A new drug on trial for IBS
Given the connection between NETs and IBS, I was really interested to see this in a UK national newspaper and I subsequently researched for some formal papers to back up the headline. What I found most interesting was the suggestion that a drug designed to inhibit serotonin was involved (…… but read on rather than get too excited).
Diarrhea – the IBS and NET Effect
Diarrhea is a big feature of IBS although there are several types including diarrhea mainly, constipation mainly and a mixed of both – you can read more in my IBS article linked above. Diarrhea is also a big feature of several of the NET Syndromes, in particular Carcinoid Syndrome. It is known that the cause of carcinoid syndrome diarrhea is the oversecretion of serotonin. This makes is quite distinct from other reasons for diarrhea, including but not limited to side effects of intestinal surgery (as one example).
Clinical Trial: Treatment of IBS with diarrhoea – titrated ondansetron (TRITON)
What is ‘ondansetron’. It’s actually a powerful anti-sickness drug given to cancer patients and some of you may recognise it as ZOFRON. Interestingly it’s a serotonin receptor (5-HT3) antagonist (5HT3-RA) for antineoplastic chemotherapy-induced nausea and vomiting. Ondansetron is a drug which blocks the 5-HT receptor, which is used to treat nausea and sickness, and has an excellent safety record. Other 5HT3-RAs include Tropisetron, Granisetron, Dolasetron, Palonosetron, Ramosetron (the group of drugs in the class known as 5HT3-RAs are known a ‘setrons’).
It is being offered to those with irritable bowel syndrome (IBS), helping to ease the most embarrassing and painful symptoms of the condition. According to the Daily Mail, if the trial is successful, it could throw open the doors to the first targeted treatment for the millions of IBS patients with bloating, abdominal discomfort and urgent bowel movements. Two people on the trial are featured in the newspaper article reporting good outcomes.
Information on the Trial. Researchers are hoping to recruit 400 volunteers in the UK aged over 18 who have IBS to take part in the 12-week study. You can read more about the trial in the reference documents below.
I guess many of you will now be thinking that but I advise not to get too excited as things are never that straightforward. However, if I was a pharmaceutical involved in NET research, I would certainly be watching this trial carefully. None of us know the interaction between NETs, NET treatments and titrated ondansetron and its mechanism of action. It may be more directed at brain and central nervous serotonin rather than gut serotonin which is mainly the issue with carcinoid syndrome diarrhea, i.e. it may not work in the same way and/or have the same effect as other approved NET drugs such as somatostatin analogues (Octreotide/Lanreotide) and tryptophan 5-hydroxylase (TPH) inhibitors such as XERMELO.
Still, it’s an exciting trial.
I will keep this article live for any developments. Finally please note this is not in any way medical advice and not a recommendation to try these drugs to control your diarrhea.
In my neck of the woods, “did you hear the one about the ………” is normally a precursor to a witty comment, or a joke. However, constipation for NET patients is not actually funny – read on.
Certain types of Neuroendocrine Cancer are very heavily associated with diarrhea, either as a symptom of one of the NET Syndromes (yes there is more than one …..); or as a result of surgery or certain other treatments. Occasionally, these symptoms and side effects can all combine to make it quite a nasty and worrying side effect.
I must admit to being surprised to find myself with feelings of constipation from around 4-5 years after my treatment and I set about trying to find out why that might be. To understand why I got to this stage, I assessed the history of my treatment and what I changed in an attempt to improve my Quality of Life (QoL) – I feel there is a strong connection.
When I underwent my primary surgery (Nov 2010), my surgeon said it would take months for my ‘digestive system’ to return to some form of normality. I soon found out what he meant, I seemed to be permanently affixed to a toilet seat (plenty of reading opportunities though ….. every cloud!). I suddenly realised that I needed to start looking seriously at my diet. I did find some improvements by trying to eat things that would bulk up my stools vs trying to avoid things that might increase frequency (i.e. I wanted a reduction in frequency combined with a bulkier stool). Eventually, I settled on a regime for the first couple of years and to be honest, I didn’t need to change my diet in any radical sense. I was also determined not to take any medication (I was taking enough) and wanted this to work as naturally as possible.
Things were still not ideal and in 2013, I even remember saying to my Oncologist that although I was never misdiagnosed with IBS, I felt like I now had it. I decided to attack this issue following professional advice from one of the eminent experts in the NET specialist dietitian world – Tara Whyand. My regime was now based on science (although it isn’t really an exact type!), that is checking the ‘at risk’ nutrient levels were OK (particularly ADEK and B12), taking supplements where necessary to help with deficiencies, and tackling things such as malabsorptionand diet.
The patient has a big part to play in any improvement strategy, so in 2013/14 I experimented more and completely changed my breakfast and lunch regime to oatmeal/porridge and toast which made a significant difference. I started to avoid eating large meals and I reduced fat consumption generally. I started taking probiotics to counter the effect of any bacterial imbalance as a result of my surgery (i.e. to combat SIBO). To keep track of everything, I set up and maintained a detailed diary to help identify things making it worse, tinkering as I went along. For those who are contemplating this sort of strategy, let me tell you – it takes time, effort and patience!
I seemed to make excellent progress with ‘frequency’, which is down to once or twice per day – i.e. I felt like a normal bloke 🙂 Quality was not consistently good but I’m of the opinion, this may be something I need to live with. Stomach cramps are reduced, as is gas and bloating reduced (I’m fairly confident that is mainly down to probiotics). Happy days, my strategy has worked. I reduced my average daily ‘visits’ by 400% without any medicine.
However …. (have you noticed, there’s always a ‘however’ with NET cancer?).
Although I’m generally well, I did start to think in 2016 that the balance was not quite right. My ‘visits’ were starting to last longer due to a consistent feeling of incomplete emptying – i.e. movement is OK but is followed by what seems like constipation. Additionally, I’ve had several episodes of constipation and pain with no ‘movement’ for 24-36 hours. This happened in May, September and December 2016. Had 3 more episodes in 2017 and 2 so far in 2018. My diary now has numerous ‘zero’ entries in the daily bowel movements column, something I never thought I would see again in my lifetime!
When you’ve had small intestinal surgery, as many midgut NET patients have, this sort of thing can be extremely worrying. A bowel obstruction can be dangerous and I’d like to avoid additional surgery at this stage. The second occurrence was particularly severe and the pain lasted for 1-2 weeks. Fortunately, the issues eventually settled and appear to have been a result of a sluggish system, although my regular scans check to see if any issues in that area might have been contributing. (Note – lactulose (oral) is awful, will never touch it again!). I seem to remember a few years ago thinking constipation would be a luxury. I can assure you it isn’t – things need to keep moving, the opposite is much worse!
So … am I a victim of my own dietary regime success? Possibly. The GP who assessed my constipation and pain in September 2016 told me to stop taking a Calcium supplement which was prescribed by the same practice at the beginning of that year – Calcium can slow your system down apparently (…..the calcium is a long story but it was a counter to an osteoporosis risk that I have due to long-term use of blood thinners). I already get enough calcium (and vitamin D) through the normal channels plus supplements, so it was a low risk action. I tinkered with my diet again, reducing my fibre intake and then built up again slowly. Additionally, I could probably do with more water! Perhaps my Lanreotide is having some effect too? In 2018, I changed my bread to one with less fibre as a test, nothing to report so far.
Is it just me with constipation issues? No….. I carried out some covert searches on forums and found this issue has been mentioned numerous times.
I suspect we need science and some specialist NET research in this area, not sure the over the counter prescription is the optimum solution. I was therefore delighted to see a patient survey produced by NET Patient Foundation in conjunction with the Royal Free Hospital presented right in front of me in Barcelona at ENETS 2018. In this survey (which I remember completing), they found that the most self reported side effect of somatostatin analogues was in actual fact constipation (shock horror!).
As you can see from the picture, the survey results came along with some pertinent advice which you will already find in some of my articles co-authored by Tara Whyand who was involved in the survey results analysis. Interestingly, Tara commented on the constipation figure pointing out that the constipated feeling may in fact be confused with ‘incomplete emptying’ as I indicated I was experiencing above. I think she’s right.
I’m always skeptical about patient surveys as they tend to be gathered from a very small percentage of the actual patient population and tend to be sourced from those with the worst issues (something I call ‘situating the appreciation’). There’s a little skepticism in me about this particular survey, mainly because the results were not scientifically investigated i.e. were these self-reported side effects actually caused by somatostatin analogues or something else?
However, many of the things reported in this patient survey are issues that I know patients tend to talk about anecdotally in patient forums. Some of them are already listed on patient information leaflets (often without patients knowing I might add) so this is further confirmation of the official trial results. Wide variances or new unlisted issues probably need looking at though.
Despite some of these side effects being listed, I believe doctors need to provide more support for patients who experience these issues. So, even if constipation (or incomplete emptying) is not totally caused by somatostatin analogues, at least this survey should start up a dialogue.
p.s. I recently started taking Pancreatic Enzyme Replacement Therapy to combat some of the well known side effects of somatostatin analogues but not yet evaluated their overall impact with the above story. Read about this and a Q & A session with Tara Whyand in this article – click here
Look on any site about Neuroendocrine Tumours (NETs) and you’ll find the term IBS (Irritable Bowel Syndrome) frequently mentioned. That’s because it’s a common misdiagnosis for many before being formally diagnosed with NETs.
But what exactly is IBS, why is it such a common misdiagnosis for many NET patients and how can these misdiagnoses be prevented or reduced in future? I just spent a few hours doing an online training course on IBS and I want to pass on some stuff I found to be very useful. I have never been diagnosed with IBS but having researched the issue through some training, I can understand why it might be in the thoughts of a general practitioner for many scenarios. Much of my research was focussed on the British Society of Gastroenterology (BSG) who sponsored the online course I completed which also used material from their magazine Gut, a leading international journal in gastroenterology.
What is IBS?
Irritable bowel syndrome (IBS) is a common, long-term condition of the digestive system. It can cause bouts of stomach cramps, bloating and excessive wind, diarrhoea and/or constipation, feeling of incomplete emptying, mucus in stool; and many other symptoms (see NHS IBS site) The symptoms vary between individuals and affect some people more severely than others. They tend to come and go in periods lasting a few days to a few months at a time, often during times of stress or after eating certain foods. IBS is a heterogeneous condition with a range of treatments. There are in fact different classifications of IBS and the diagram below supports the list with some context:
IBS-D – diarrhea based
IBS-C – constipation based
IBS-M – mix of both diarrhea and constipation
You can see why someone presenting with diarrhea or IBS-D type symptoms might be automatically assumed to have IBS despite the fact that these symptoms could also apply to many other conditions including several cancers. However, what I also found is that in the UK, there is now updated guidance from NICE (National Institute for Health and Care Excellence) to aid GPs and other physicians on how to properly diagnose IBS. In fact, the online course I undertook is one of many now being offered to medical staff as part of the new guidance. That sounds like a good thing in practice (although I did notice some differences between the BSG recommendations and what is published by NICE…….. £ )
How is IBS diagnosed?
That is considerably complex as the symptoms are fairly general. However, I was encouraged to find that doctors should assess any ‘red flag’ indicators that would need referral to secondary care before any firm decision on IBS was made. These include (but not limited to), unintentional and unexplained weight loss, rectal bleeding, family history of bowel or ovarian cancer, a change in bowel habit to looser and/or more frequent stools persisting for more than 6 weeks in a person aged over 60 years, anaemia, abdominal masses, rectal masses, inflammatory markers for inflammatory bowel disease. That’s very interesting because in 2010, after mentioning some unintentional weight loss, my GP said ‘anaemia’ to me and referred me to secondary care. Perhaps I was lucky but perhaps, my GP’s team were just professional and thorough? That said, if you’re with me so far, you can see why IBS might be an easy diagnosis to make for someone presenting with either diarrhea/constipation issues with no other obvious symptoms or abnormal test results (particularly IBS-D).
Why might NETs be frequently misdiagnosed as IBS?
Using the NICE guidelines, I noted there are a range of tests to preclude other diagnoses including: full blood count (FBC), erythrocyte sedimentation rate (ESR) or plasma viscosity, c‑reactive protein (CRP), antibody testing for Coeliac disease. Whilst abnormal results of these tests might show up something to investigate further (i.e. FBC – haemoglobin worked for me), none of them include looking ‘inside’ the patient and I guess there is a resource/finance issue involved here.
In fact, the guidelines also list a number of tests that are NOT necessary to confirm a diagnosis of IBS. These include: ultrasound, rigid/flexible sigmoidoscopy, colonoscopy, barium enema, thyroid function test, faecal ova and parasite test, faecal occult blood, hydrogen breath test. You can see the issues ………..
The guidelines go on to say that a diagnosis of IBS should be considered only if the person has abdominal pain or discomfort that is either relieved by defecation or associated with altered bowel frequency or stool form. This should be accompanied by at least two of the following four symptoms:
abdominal bloating (more common in women than men), distension, tension or hardness
symptoms made worse by eating
passage of mucus.
Other features such as lethargy, nausea, backache and bladder symptoms are common in people with IBS, and may also be used to support the diagnosis
I also noted that the causes of IBS are inextricably linked with Psychological issues and the guidance also includes therapies including cognitive behavioural therapies (CBT) relaxation therapies, and hypnosis.
So if you’re one of the unlucky ones who has presented with “IBS like” symptoms and have normal test results as per above, you may not get the opportunity to get to further testing to find the true diagnosis. It’s possible that you saw a physician who has not followed guidelines for diagnosing IBS, if indeed such guidelines were available to him/her. The inclusion of psychological issues also connects with many anecdotal stories of NET patients being told they needed psychological help before eventually being diagnosed with NETs.
I can see many similarities in the descriptions of IBS symptoms and the sort of things you can read on NET forums – curiously including the effects of NET Cancer surgery and other treatment after diagnosis.
Slight digression but if this subject is of interest, you may like to comment. I once said to my Oncologist that I felt as if I had IBS since my surgery and somatostatin analogue treatment. In fact, I told him that I thought my bowel was more than irritated, it was bloody angry 🙂 During my research, I couldn’t help noticing that some of the suggestions and recommendations for IBS are similar to that offered to a post surgical NET patient. You may therefore like my blog series on Nutrition which was co-authored by a NET specialist dietician who is also IBS aware.
Preventing or Reducing a Misdiagnosis of IBS (all illnesses)
The course looked at this angle as it was clearly keen to emphasise this to medical people going through the module. The NICE guidelines read like a process which must be strictly followed but at the end of the day, they are just ‘guidance’ and should not stop doctors thinking outside the box.
A recent study suggested that as many as 1 in 6 patients (~16%) with symptoms of IBS had another disease. Approximately 7% had Crohn’s disease, 3% coeliac disease, and 2% microscopic colitis when they were formally tested. Patients with IBS-diarrhoea predominant more often had abnormalities than those with IBS-constipation predominant (interesting for NETs). The paper stresses the importance of tailored investigation of patients presenting for the first time.
One in six patients with symptoms compatible with IBS without alarm features in this selected group exhibited organic GI disease following investigation. Assessment of alarm features in a comprehensive history is vital to reduce diagnostic uncertainty that can surround IBS. You can, if you wish, read the abstract of the paper on the link below.
The issue here is that people not meeting the criteria for further checks may be precluded for scans and other tests due to lack of clinical evidence and their diagnosis of IBS will stand. As this was a study, clearly some of them might have gone on to present with sufficient clinical evidence to warrant more checks and subsequent diagnosis of something else at a more advanced stage. Clearly this sounds familiar with NETs. However, looking at the figures above, I suspect the figures for NETs IBS misdiagnoses are pretty small in comparison to those who are correctly diagnosed with IBS. To put that into context (in the UK), according to the NHS, IBS is thought to affect up to one in five people (10,000,000 in UK alone) at some point in their life, and it usually first develops when a person is between 20 and 30 years of age and around twice as many women are affected as men. Compare that with a UK NETs prevalence of around 40,000 (guesstimate), you can see that a misdiagnosis of IBS for NETs, is not that common. However, one misdiagnosis is one too many.
Having done this course and read the accompanying references (some only abstracts), I can see the scope for people with many different illnesses being misdiagnosed with IBS. However, the use of alarm symptoms and ref flag indicators should be helping to reduce this. I’m guessing that many people in first line care may not be fully aware of the IBS guidelines to be able to take heed. I’m also guessing that in the UK (at least), a 10 minute appointment with a busy GP is just not going to solve some of these symptom clashes and many visits might be required to move forward.
It’s really difficult to advise anyone going through a diagnosis of IBS as to how to approach a physician who says they have IBS and they think this is wrong. In the case of NETs, other cardinal symptoms may be of use in convincing physicians (e.g. flushing). Armed with this knowledge, I would say to anyone who suspects NETs but are faced with an IBS diagnosis, take a copy of the BSG and NICE guidelines to your doctor and tick off all the differential ‘ref flag’ and ‘alarms’ issues ensuring that each has been tested before accepting the IBS diagnosis.
References used to support compilation of this blog: