Digestive health disorders and diseases affect millions of individuals worldwide and its impact is reflected in decreased quality of life for the patient, healthcare costs and work absenteeism. In putting digestive diseases in perspective, most disorders can be compartmentalised into two disease categories ie; Organic and Functional Digestive Disorders.
Organic diseases are serious illnesses marked by anatomical, structural (tumours or masses) or biochemical abnormalities, as seen in Helicobacter pylori infection, colorectal cancer (CRC) and gastroesophageal reflux disease (GERD). Functional Digestive Disorders like dyspepsia, functional abdominal pain, functional constipation and functional diarrhoea, on the other hand, do not exhibit such disease characteristics.
Dr Sasikala Devi Amirthalingam, Family Medicine Physician with IMU Healthcare (IMUH) explains, “Functional bowel disorders are disorders characterised by persistent and recurring gastrointestinal (GI) symptoms that occur as a result of abnormal functioning of the GI tract.
“Abnormal motility leads to disorganised painful contractions of the gut. However, routine medical tests often produce normal or negative for disease results.”
The most common and widely researched functional digestive disorder is Irritable Bowel Syndrome or IBS. IBS is a chronic digestive disorder of the large intestine that needs to be managed in the long term.
“IBS is often characterised by abdominal pain; cramping or bloating that is typically relieved or partially relieved by passing a bowel movement; excess gas; diarrhoea or constipation, sometimes alternating bouts of diarrhoea and constipation; and mucus in the stool.
“The disorder may be caused by several factors some of which include inflammation of the intestines or an overly reactive immune-system response following a severe episode of bacterial or viral gastroenteritis and bacterial overgrowth in the intestine or changes in the gut microflora.
“IBS is more prevalent among women and people under the age of 50 who may have a family history of IBS as genes may play a role as may share factors in a family’s environment or a combination of genes and environment. Anxiety, depression and other mental health issues or a history of sexual, physical or emotional abuse are also risk factors,” says Dr Sasikala.
“Stress may aggravate symptoms of IBS as most people with IBS experience worse or more frequent signs and symptoms during periods of increased stress and while many people may have worse symptoms eating certain foods, a true food allergy rarely causes IBS,” she adds.
IBS and the gut-brain axis
According to IMUH Medical Director and Consultant Gastroenterologist and Physician, YBhg Prof Dato’ Dr (Mrs) Kew Siang Tong, prevalence rates of IBS vary from 4.4% to 21.8% and are similar in Western nations and the Far East. Studies on Asian prevalence rates are relatively scarce. However, a survey in 2003 among healthy Malaysian young adults in a public university found prevalence of 15.8%.
“IBS is classified into four subtypes: IBS with predominant constipation (IBS-C), IBS with predominant diarrhoea (IBS-D), IBS with mixed bowel habits (IBS-M) or IBS, unsubtyped. A study conducted in IMU in 2006-7 according to the Rome II criteria found prevalence of 23%, of which 35% was IBS with predominant constipation (IBS-C); 35.4% IBS with predominant diarrhoea (IBS-D); and 29.2% IBS with mixed bowel habits (IBS-M),” she says.
Dato’ Kew shares that IBS is currently diagnosed via the Rome IV (2017) criteria of recurrent abdominal pain of at least one day per week in the last 3 months with symptoms associated with a change in the frequency of stool and/ or change in the form or appearance of stool. Criterion needs to be fulfilled for 3 months with symptom onset at least 6 months prior to diagnosis.
“Symptoms that cumulatively support the diagnosis of IBS include abnormal stool frequency of more than 3 bowel movements a day or less than 3 bowel movements a week, abnormal stool form of lumpy, hard, loose or watery stool, straining, urgency, a feeling of incomplete evacuation and a feeling of abdominal distension.”
Dato’ Kew shares that Inflammatory Bowel Disease (IBD) may be confused with IBS as the symptoms are somewhat similar. IBD is a term for chronic conditions including Ulcerative Colitis and Crohn’s Disease. Long standing ulcerative colitis may evolve into colorectal cancer.
She says that unlike cancer, there is no issue with early detection for IBS. “It is more of an inconvenient disorder to have as patients worry about making it to the toilet on time, especially when they are out and about.”
Diagnosis for IBS generally involves exclusion of more serious conditions. In addition to good medical history, a physical examination that involves pelvic and rectal (PR) examinations is usually performed in evaluating a patient. Red flags include unintentional weight loss, fever, onset in an older person, family history of colorectal cancer (CRC), rectal bleeding, refractory diarrhoea, anaemia and abnormal physical signs.
Simple blood test like full blood count and ESR (erythrocyte sedimentation rate), as well as screening stools for occult blood, ova, cysts and parasites may be undertaken; and sigmoidoscopy and colonoscopy may be recommended for persons over the age of 50 or if organic disease is suspected.
Dato’ Kew says that as the pathogenesis of IBS is not clear-cut, it is often deemed a poorly understood disease with few effective treatments.
“Following an assessment, if IBS is suspected, patients will be advised to avoid certain food stuff like onions, peppers, spices, fatty and greasy foods that are known to cause discomfort,for a period of time. Later, individual food item is re-introduced, and see if symptoms recur. Patients are advised to avoid food definitely associated with precipitation of symptoms.
“Antispasmodic medication and low dose tricyclic antidepressants may be prescribed for pain and bloating; fibres and osmotic laxative for constipation; and Loperamide and Diphenoxylate for diarrhoea.”
Studies show that few patients with IBS subsequently develop organic disease. However, IBS is a relapsing disorder with two-thirds of patients experiencing symptoms even after prolonged follow-up. There is no medical therapy proven to alter the natural history of IBS.
“Nonetheless, the role of probiotics is becoming increasingly important now that gut microbiota is recognized as playing an important role in the pathogenesis of IBS and gut-brain axis.
“More and more clinical and experimental evidence also show that IBS is a combination of irritable boweland irritable brain.”
In explaining the gut-brain axis (GBA), Dato’ Kew says, “It has been well established that bidirectional interaction pathways occur between the central nervous system (CNS), gastrointestinal tract and enteric plexus. Signals from the brain can affect motility, secretion, nutrient delivery and microbial balance in the gut. Similarly, visceral signs from the GI tract can have an impact on neurotransmitters, stress levels, mood and behaviour.”
Psychological well-being and IBS
IMUH’s clinical psychologist, Puvessha Jegathisan says, “Being a stress-sensitive disorder, IBS is triggered when the body undergoes stress which in turn causes a fight-or-flight response. Enzymes and hormones are released, affecting the gut environment.”
“There is a strong correlation between the severity of IBS and its co-morbid psychiatric disorders, depression and anxiety. Major life traumas were frequently reported 38 weeks prior to onset of IBS symptoms in patient studies. Co-morbidity of IBS and psychiatric disorder is approximately 40% to 60%.”
“Social stigma continues to be the biggest hurdle that is preventing patients from seeking the psychological help they need. Most shy away from seeing a therapist for fear of being labelled crazy, feeble-minded or weak. There are yet others who do not know where to seek help.”
Puvessha shares that treatment for IBS is often viewed and approached from a holistic biopsychosocial perspective. This essentially means that counselling and psychotherapy may be applied to work in tandem with pharmacotherapy.
“The role of the clinical psychologist is to identify stress triggers so that solutions and direction can be offered to the patient to manage and prevent future episodes.”
Among the measures recommended to manage symptoms of stress include deep breathing, imagery and progressive muscle relaxation exercises and cognitive-behavioural therapy (CBT) or mindfulness-based CBT.
In CBT, patients build insight into the relationship between situations, thoughts, behaviours, physical reactions, and emotions; and learn ways to catch and change unhelpful thinking patterns and behaviours that may contribute to physical or psychological distress and to some extent, intervene on their own physiologic responses.
Many people have the misconception that being in therapy equals costly, long-drawn gut-spilling sessions at the psychologists’ office. However, if indeed there is a mental issue and the underlying issue of psychological health is not properly addressed, patients may find that they are just treating symptoms as and when they appear.
“The aim of psychotherapy is to ultimately wean the patient from being dependent on medication and therapy so he can function normally in society.”
Influence of gut microbiota on overall health
Recent advances in research have described the importance of gut microbiota in influencing interactions and biochemical signalling between the gastrointestinal tract and central nervous system.
Dietitian at IMUH’s medical clinic, Kanimolli Arasu explains that host factors like genetic background, gender, age, specific disease or birth route; and environmental factors like diet and lifestyle, hygiene, medication and geography affect microbiota.
“Early life exposure like vaginal delivery where the infant is exposed to maternal microbes; subsequent infant diet; antibiotics which results in selective killing of microbes; probiotics which results in selective enrichment; and the physical environment where an individual is exposed to environmental microbes as well as subsequent adult lifestyle choices have been known to impact upon gut microbiota.
“In the case of symbiosis, where a good balance of microbiota is achieved, an individual benefit from healthy metabolism, immune tolerance and intestinal homeostasis. When microbial imbalance occurs, a person may become pre-disposed to non-communicable diseases (NCDs) of the immune system like asthma and multiple sclerosis and intestinal disorders like necrotising enterocolitis and IBD.
Kanimolli says prebiotics like FOS, GOS, Inulin, isomaltulose and Soluble corn fibre found in foods such as leek, onions, garlic, Jerusalem artichoke, wheat bran, oats, legumes, soy beans, asparagus, corn and raw banana support optimum gut function in favour of the proliferation of normal bacterial flora and inhibit the growth of pathogenic organisms. The changes in microbiota induces softer stools, increases stool frequency and reduces incidences of travellers’ diarrhoea.
Probiotics, which are present in foods like yogurt, cheese, kefir, miso, kimchi, sauerkraut, tempeh and kombucha is useful adjunct to rehydration therapy in treating acute, infectious diarrhoea in adults and children and improves chronic constipation in children. In IBS, probiotics appear to be beneficial in terms of improved clinical symptoms.
Although there have been multitude of studies and tests done on prebiotic and probiotic strains more than 200 strains and combination of strains to date) in different dosage formats (5-20g) on various health conditions, there is no specific indication as documented benefits are strain and dose dependent. There is evidence however that changes in microbiota after supplementation with prebiotics and probiotics is rapid but microbiota changes when supplementation is stopped.
Kanimolli advises that for optimal gut health, it is best to combine prebiotic and probiotic-rich foods for symbiotic effect. “You could have yogurt with banana slices, stir-fried asparagus with tempeh and miso soup with cubes of tofu.
“Consuming a variety of plant-based foods will confer the benefit of different fibres and nutrients for a more diverse microbiota.”