Irritable bowel syndrome (IBS)

Irritable Bowel Syndrome (腸易激綜合症), commonly known as "sensitive bowel", is a ubiquitous digestive system functional disorder with an as yet unknown identifiable cause. The main symptoms of irritable bowel syndrome include abdominal pain, bloating, abdominal discomfort, and changes in bowel habits that can significantly affect a person’s daily life and social interactions.   

Causes of Irritable Bowel Syndrome  

Intestinal function 

• Intestinal peristalsis is too fast or too slow, affecting digestion 
• Intestinal nerves are overly sensitive 
• The gut sends mixed messages to the brain 

External influence 

• Food that irritates the intestines, such as alcohol, caffeine, spicy or fatty foods 
• Psychological stress, such as tension and anxiety 
• Family history/genetic factors 
• Environmental factors such as work and relationships 
• Alterations in fecal microflora/bacterial overgrowth

Symptoms of Irritable Bowel Syndrome 

Irritable bowel syndrome typically causes the following symptoms, which may come and go for days or even months: 

• Belly pain/stomach cramps: Especially severe after eating, but relieved by bowel movements 
• Bloating: Abdominal discomfort such as fullness or distension 
• Diarrhea: Passage of loose, watery stools, or frequent defecation of such
• Constipation: Difficult passage of lumpy or hard stools, often with strainingIn addition, people with irritable bowel syndrome may also experience the following symptoms: 

Diagnosis of Irritable Bowel Syndrome: The ROME IV Criteria (2016) 

The Rome Foundation, a not-for-profit organization, with an international committee of experts, aimed at gathering scientific data to aid in the diagnosis and treatment of functional gastrointestinal conditions, has set forth the following diagnostic criteria* for irritable bowel syndrome: 

• Recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following criteria: 

1. Related to defecation 
2. Associated with a change in frequency of stool 
3. Associated with a change in form (appearance) of stool 

*Criteria fulfilled for the last 3 months with symptom onset at least 6 months before diagnosis 

In addition, the following subtypes of IBS are currently recognized: 

1. IBS with predominant constipation (IBS-C) - predominantly passes hard stools 
2. IBS with predominant diarrhea (IBS-D) - predominantly diarrheic stools 
3. IBS with mixed bowel habits (IDB-M) - usually complains of both diarrhea and constipation 
4. IBS unclassified (IBS-U) - fulfills the IBS Rome criteria but abnormal stools are rare 

• Colonoscopy, laboratory tests and diagnosis of exclusion (“rule-out” method) 

The utility of colonoscopy in IBS is the direct assessment of the internal surface anatomy of the terminal ileum (last part of the small intestines) and the colon (large bowel). It is useful to visually examine if tumors (benign, malignant or pre-malignant), inflammation, ulcers, abnormal blood vessels, bleeding or diverticula (outpouching in the walls of the bowels) are present that might be the cause of the GI symptoms and provide an avenue for tissue biopsy. Complementing colonoscopy would be laboratory examinations from simple complete blood counts, routine stool and occult blood exams to more specific ones like for celiac disease e.g. tTg IgA Test, deaminated gliadin IgG & IgA test, IgA endomyseal antibody (EMA) test) or inflammatory bowel disease (Crohn’s or ulcerative colitis) e.g. CRP, fecal lactoferrin (Lf), calprotectin (Cal), polymorphonuclear neutrophil elastase (PMN-e). The absence of any significant findings among these “ruled-out” investigations, a consideration for irritable bowel syndrome (IBS) can now be made. 

Treatments for Irritable Bowel Syndrome 

• Medical treatment 

There is currently no cure for irritable bowel syndrome, but medications prescribed by doctors can effectively relieve the symptoms and reduce their impact on patients' lives. For the common symptoms mentioned above, medicines prescribed by your doctor may include: 

It may take several weeks for the medicines to take effect. In addition, depending on the cause and extent, doctors may recommend patients take antidepressants or refer patients to receive psychological counselling to to address the psychological impact (or component) of irritable bowel syndrome. 

• Psychological counselling   

When irritable bowel syndrome persists, or the above treatments fail to work, you can choose to meet with a psychotherapist and utilize psychological interventions like cognitive behavioural therapy, hypnosis and mindfulness-based therapies. This can help relieve tension or anxiety and reduce the frequency and severity of symptoms. 

Irritable bowel syndrome care 

✔ Should 

• Develop healthy eating habits, including cooking your meals 
• Keep a food diary to track food triggers 
• Release stress and emotions at the right time 
• Do exercise regularly 
• You can try taking probiotics for a month to evaluate their effectiveness 

✘ Should not 

• Eating at irregular times or skipping meals 
• Eating too fast and neglecting to chew 
• Eating foods that irritate your intestines (such as spicy, fatty and processed foods) 
• Overeating hard-to-digest food (such as taro, glutinous rice, sweet potato) 
• Drinking caffeine or carbonated drinks (such as coffee, tea, and soda) 
• Addicted to smoking and drinking

Low FODMAP diet 

In addition to following the above suggestions, you can choose appropriate foods according to the "Low FODMAP Diet" to reduce the load caused by diet on the intestines. FODMAP is a large class of small nondigestible, poorly absorbed carbohydrates. Their microscopic size, high osmotic activity, and higher fermentation by colonic bacteria lead to bloating, abdominal pain, and flatulence worsening IBS.  

FODMAP means

You can also read our recent blog about low-FODMAP and high-FODMAP foods in the UK’s Gloucestershire hospitals (NHS Foundation Trust) and our blog. 

Here are some common FODMAP foods that are suitable for people with irritable bowel syndrome: 

• Rice, rice noodles 
• Unprocessed meat, fish, eggs, cheese 
• Broccoli, cucumber, lettuce, tomato, potato, pumpkin, radish 
• Blueberries, strawberries, kiwi, lemon 
• Oat milk (a small amount), almond milk, peanuts, walnuts, mung beans 
• Dark chocolate 
• Gluten free diet 

OT&P Medical Advice 

Regardless of whether you have IBS or not, everyone should develop a gut-friendly balanced diet and be able to establish good bowel habits. For any persistent gastrointestinal complaints such as bloating, abdominal cramps, changes in bowel habits and more that interfere with the daily life-work-sleep-social cycles, it is recommended to seek medical advice to address and manage the cause at the earliest. At OT&P we offer general practice and specialist consultations to cater to your medical queries and needs. 

References 

1. NHS. What is IBS? 19 Dec 2023 Retrieved from https://www.nhs.uk/conditions/irritable-bowel-syndrome-ibs/  
2. Mayo Clinic. Irritable bowel syndrome. 19 Dec 2023 Retrieved from https://www.mayoclinic.org/diseases-conditions/irritable-bowel-syndrome/symptoms-causes/syc-20360016  
3. Cleveland Clinic. Irritable Bowel Syndrome (IBS). 19 Dec 2023 Retrieved from https://my.clevelandclinic.org/health/diseases/4342-irritable-bowel-syndrome-ibs  
4. Johns Hopkins Medicine. Irritable Bowel Syndrome (IBS). 19 Dec 2023 Retrieved from https://www.hopkinsmedicine.org/health/conditions-and-diseases/irritable-bowel-syndrome-ibs  
5. The Rome Foundation, Rome IV Criteria. 2016. Retrieved on 20 February 2024, from https://theromefoundation.org/rome-iv/rome-iv-criteria/