Author: P J Whorwell / Editor: Charlotte Davies / Codes: CAP1, CAP2, HAP1 / Published: 10/09/2019
“Toni is a 35 year old lady who attends the emergency department regularly with chest pain. Nothing seems to make it better, and her troponin is always normal. You wonder if there is a potential cause. Read on to find out that there is more to IBS than abdominal pain.”
The characteristic symptoms of irritable bowel syndrome (IBS) are abdominal pain, abdominal bloating or distension coupled with a disordered bowel habit in the form or constipation, diarrhoea or an alternation between the two. In addition, many patients also suffer from a range of ‘non-colonic symptoms’ such as low backache, constant lethargy, chest pain, urinary frequency or urgency and in females, gynaecological symptoms.
In approximately 50% of patients, their symptoms are relatively mild and they seldom, if ever, consult. However, in the remainder, symptoms can be much more intrusive and unfortunately it is not generally appreciated just how severe they can be. For instance, women often equate their abdominal pain to that of childbirth and the abdominal distension can mimic late pregnancy. The non-colonic symptoms can result in referral to the wrong specialty such as orthopaedics, endocrinology, urology or gynaecology. The chest pain can mimic angina resulting in attendances at rapid access chest pain clinics or emergency departments. Not surprisingly, with this degree of symptom severity coupled with the tendency for the medical profession to trivialise IBS, patients can become very distressed which then perpetuates the misconception that IBS is a purely psychological illness. Of course, psychological factors will tend to make their symptoms worse, but they should not be considered as the cause.
All investigations in patients with IBS will inevitably be negative as it is a disorder of function of the whole length of the gastrointestinal system rather than being a structural problem. Consequently, investigations should be limited to ruling out realistic alternatives for the cause of a particular patient’s symptoms rather than being exhaustive. Nothing disillusions a patient more than being told that all the tests are ‘normal’ with the implication that there is nothing wrong with them.
The severity of a particular symptom varies from patient to patient but when the abdominal pain or chest pain is the most prominent feature, these are the individuals who are more likely to attend the ED. The abdominal pain can occur at any site and is frequently described as squeezing, twisting or stabbing. It is not uncommon for it to be accompanied by vomiting. Unfortunately, by the time patients get to this stage they are not infrequently taking morphine and their attendance at an Emergency Department can sometimes be viewed as drug seeking behaviour. If at all possible, opiates should never form part of the management of severe IBS as they can actually exacerbate the pain (narcotic bowel syndrome) as well as adversely affecting bowel function. In the acute situation, intravenous Buscopan is a good choice and can be repeated as necessary. Furthermore, a response to Buscopan confirms the diagnosis of gastrointestinal spasm as it has no analgesic properties. If necessary, the use of Buscopan can be coupled with intravenous paracetamol. Not surprisingly patients are often distressed by the intensity of their pain and diazepam can be very helpful in this situation. If there is vomiting, the diazepam should be administered rectally.
The chest pain that can accompany IBS can be almost indistinguishable from cardiac chest pain especially as it can radiate to the left arm, neck and jaw. It also often responds well to glyceryl trinitrate (GTN). One feature that can support the diagnosis of non-cardiac chest pain (NCCP) is radiation of the pain to the middle of the back which is relatively uncommon in angina. Of course, in the acute situation cardiovascular causes for the pain need to be ruled out but in someone who has been previously investigated, NCCP needs to be considered. The treatment of acute NCCP can be difficult but it is worth trying GTN. In addition, patients often respond well to diazepam especially when they are distressed. Intravenous Buscopan or paracetamol are also worth trying. One important component of the management of NCCP is to try and reduce the frequency of attacks and for this purpose tricycylic antidepressants have been shown to have significant effects.
Once a patient with an acute attack of IBS has been stabilized, it is important that their condition is improved otherwise they will continue consulting. Education is a key component. Patients need to understand that negative tests are to be expected, that pain of the intensity that they are experiencing is common in IBS and that although the condition cannot be cured, it can usually be effectively managed.
Interestingly, a ‘healthy diet’ tends to make IBS worse and it is worth advising patients to try the low FODMAP diet and reduce their fibre intake. It is also important to establish as much as possible, a reasonably normal bowel habit with laxatives in constipated individuals or loperamide in those with diarrhoea. It is a fallacy that laxatives damage the bowel and patients should be encouraged to use the lowest dose on a daily basis that results in a reasonably satisfactory bowel function. They always need to be reassured that this approach is safe and will not make their bowel ‘more lazy’. Similarly, the regular use of loperamide in those with diarrhoea can be helpful although they need to be warned that the dose needs reducing if they become constipated. For pain, Buscopan is very effective although only 10% of the drug is absorbed when it is taken orally. Consequently, some patients have to take more than the recommended dose, such as 4 or 6 tablets at once repeated as necessary. ED attendances can often be significantly reduced or prevented by the self-administration of intramuscular Buscopan on an as necessary basis for acute attacks. Antidepressants, particularly those of the tricyclic variety, are often very helpful as a long term management option. However, it should be emphasized to the patient that they are being used for their effect on the gastrointestinal system rather than because they are just ‘depressed’.
For the frequent ED attender with abdominal or chest pain, the presence of abdominal bloating or distension and bowel dysfunction should raise the suspicion of a functional gastrointestinal disorder such as IBS. It has been shown that the presence of non-colonic symptoms including low backache, constant lethargy, nausea and bladder symptoms also help to substantiate the diagnosis. Patients might also gain some useful self management tips from ‘take control of your IBS‘ by PJ Whorwell.