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).  This overlaps with the selection or balance of low and high residue foods.  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 malabsorption and 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!  And remember, what works for one may not work for another – there is no single diet which works for all patients.

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 Neuroendocrine 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 changes to my 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 (edit – I flit between different types of bread but appear to be settled on oaty bread or granary).

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.