With IBS, the rule is: ‘there are no rules’
…. there is only the patient.
Mandy wrote to me recently to tell me how much better her diarrhoea had been since she started taking Questran, a ion exchange resin which mops up unabsorbed bile acid, which irritates the colon. But recently, she had found that just one sachet a day, taken as advised half an hour before the main meal of the day, had left her constipated. She had split the dose, taking just a half a sachet and then just a quarter of a sachet a day, but remained constipated. I suggested that she stop it and she try to manage the constipation by adjusting her diet, perhaps adding beetroot or prune juice to stimulate bowel movements by retaining more fluid in the gut. Mandy was reluctant to do this as she had been told by her dietitian that the treatment for IBS was a low FODMAP diet, and beetroot and prune juice were high in FODMAPs. It was against the rules! So she stayed on her diet and continued to be constipated. Soon, she was pretty fed up, so her doctor prescribed amitriptylene to lighten her mood. The problem was it seemed to make the constipation worse.
Treatments for IBS tend to assume that the features of the illness are constant. That is never the case. Often, the only thing that is constant about them is that they change. Fluctuating symptoms require adaptable management. Diarrhoea and constipation are physiologically opposed and require different polarities of treatment.
If you have suffered with IBS for years, you will have no doubt become rather sceptical of claims of a ‘cause’ for IBS or a ‘universally effective treatment’. IBS often develops in response to variable combinations of factors: stress, diet, colonic bacteria, immunological, physiological, infective, etc. A variety of treatments, including high fibre diets, low FODMAP diets, serotonin analogues or antagonists, antibiotics, cognitive behavioural treatment, have enjoyed initial enthusiasms and endorsements, but have rarely lived up to expectations in the longer term. Often it is a case of trying one treatment until it loses its effect or the symptoms change and then trying something else.
IBS is an illness that disobeys the rules; it does not have a specific cause, a definitive diagnosis or a single effective treatment. It is neither all in the gut, nor all in the mind. There is not a specific disturbance of the colonic microbiome, nor a specific immunological abnormality, a specific disturbance of physiology, or a genetic disease, but the illness may encompass abnormalities in all of these. There are no objective diagnostic criteria or specific diagnostic tests for IBS.
Successive Rome Committees have attempted to establish positive diagnostic criteria for IBS, but these all carry the caveat that organic illness that gives rise to the same symptoms must be excluded. Yet the committees remain strenuously opposed to the notion that IBS is to all intents and purposes a ‘diagnosis of exclusion’. The NICE guidelines for the management of IBS attempt to set out an algorithm for best practice, but experienced GPs understand that their patients do not necessarily conform to the descriptors and guidelines always need to be adjusted according to the condition and situation of the particular patient, applying appropriate therapies or medications to stabilise fluctuations in emotional tension and bowel tone while foster self understanding and self management.
For background information on the topics mentioned in this post, join an log into The IBS Network and look up the relevant sections of of The IBS Self Care Plan (What is IBS?, FODMAPs, Constipation medicines, How can I manage my diarrhoea?)
The Sensitive Gut 