SF | CPD: GASTROENTEROLOGY
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July 2020 | Vol. 20 No. 6 www.medicalacademic.co.za
This article was independently sourced by Specialist Forum.
A natural approach to IBS, backed by science Motility disorders, which can affect any part of the gastrointestinal (GI) tract, are characterised by abnormal movements, causing the abnormal transit of contents - either too fast or too slow - in the absence of mucosal disease or obstruction. Motility is a huge problem in irritable bowel syndrome (IBS), one of the most common disorders of gut–brain interaction worldwide.1,3
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BS is defined according to patterns of GI symptoms. Rome IV defines IBS as a functional bowel disorder in which recurrent abdominal pain is associated with defecation or a change in bowel habits.1,2 Disordered bowel habits are typically present (eg constipation, diarrhoea or a mix of constipation and diarrhoea), as are symptoms of abdominal bloating/distension. Symptom onset should occur at least six months prior to diagnosis and symptoms should be present during the last three months.2
IBS subtypes Patients with IBS are classified into specific subtypes, which is based on the predominant bowel habit. Classifying patients according to these subtypes can aid clinicians in decisionmaking regarding management. The four subtypes are: IBS with predominant constipation (IBS-C) IBS with predominant diarrhoea (IBS-D)
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With mixed bowel habits (IBS-M) IBS, unsubtyped.
More than 50% of patients with IBS have either IBS-D or IBS-M. Bristol stool types 1 and 2 or types 6 and 7 are considered abnormal. 2,5
Diagnostic challenges The diagnosis of IBS can be difficult for a
number of reasons:2 » Symptoms may change over time, and these fluctuations may make the clinician feel as if the disorder is more complicated than it truly is » Symptoms of IBS may mimic other disorders (eg lactose or fructose intolerance) and thus may fail to respond to empiric treatment » Clinicians may not be aware of current guidelines or definitions on how to properly make the diagnosis of IBS » A precise biomarker for IBS does not exist — patients may have persistent or recurrent symptoms but clinicians cannot order a test to confidently diagnose the condition » Patients may want testing to identify the cause of their symptoms, although routine tests generally result as normal, which is frustrating to the patient, since symptoms persist.
What causes IBS? Although it is still unclear what causes IBS, numerous studies have postulated that enteric infections, immunomodulation, visceral hypersensitivity, and an imbalance in neurotransmitters may all play a role in the development of IBS.14 Importantly, alterations in the gut microbiota can induce changes in gut motility, permeability, food processing and visceral perception which eventually leads to the occurrence of IBS-related symptoms.14 Studies have also shown that IBS patients experience bacterial overgrowth in the small intestine or altered GI microbes. A
meta-analysis observed that patients with IBS (particularly IBS-D) have significantly reduced GI colonies of Bifidobacterium, Lactobacillus and Faecalibacterium prausnitzii bacteria compared to healthy individuals.14 Furthermore, the link between GI microbial disruption and IBS is corroborated by the fact that 10%–53% of patients are diagnosed with IBS following a GI infection.14
How is IBS treated? Management of IBS is complicated due to the lack of consensus regarding the causes of IBS, states the World Gastroenterology Organisation (WGO). As a result, no single treatment is currently regarded as being universally applicable to the management of IBS patients.4 Treatment goals are aimed at resolving symptoms such as pain, bloating, cramping, and diarrhoea or constipation. Pharmacotherapy includes:4,7 » Antispasmodics for pain » Laxatives, fibre, and bulking agents for constipation » Fibre, bulking agents, and anti-diarrheals for diarrhea » Charcoal resins, antiflatulents, and other agents are widely used, although without supporting evidence, for bloating, distension, and flatulence » Tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) are effective for symptom relief in IBS. Adverse effects are common, with
