April 18, 2022

Introduction

Irritable bowel syndrome, or IBS for short, is also a condition known as ‘sensitive gut’. It is a relatively common long-term digestive system condition. It is found that about 11.2% of people worldwide suffer from IBS¹, although the prevalence may be different across different countries, with other studies citing a prevalence of about 4.4% to 4.8% in the United States, Canada and United Kingdom².

It is characterized with frequent abdominal pain coupled with symptoms of constipation and/or diarrhea. What are the other symptoms one with IBS will usually face, and how is it being managed and treated? Read on to find out more!

What are the different types of irritable bowel syndrome (IBS)?

IBS is generally divided into 3 types³:

• IBS-D (diarrhea)
• IBS-C (constipation)
• IBS-M (mixed), or also known as IBS-A (alternating)

Although there are no tests for IBS, doctors may do blood tests to rule out other possible conditions causing similar symptoms as IBS, including celiac diseases or inflammatory bowel diseases⁴. Your doctor may use a certain set of criteria called Rome IV diagnostic criteria, which evaluates based on the pattern and frequency of abdominal pain and its association with bowel movement, as well as whether there is a change in the frequency and consistency of your stools⁵.

The doctors will then categorization based on the predominant stool consistency, based on the Bristol Stool Form Scale (BSFS) and the Rome IV criteria.

What are the causes and risk factors of irritable bowel syndrome (IBS)?

Although we do not know the actual cause of why IBS occurs, there have been different postulations as to why IBS develops in some people. One possible issue could be with the gut-brain axis interaction, which is also called functional gastrointestinal (GI) disorder⁶. This occurs when there are issues with how your brain and gut works together, which affects the sensitivity of your gut. This interaction also affects the bowel muscles functions, which may explain the symptoms experienced by patients suffering from IBS.

Some conditions and diseases may also make someone more prone to getting IBS. You may be at higher risk of developing IBS if you have^6,7:

• A family history of IBS
• Emotional stressors, tensions, or anxiety
• Bacterial infections of the gut
• Intolerance to certain foods
• Certain genetic composition

What are the signs and symptoms of irritable bowel syndrome (IBS)?

Patients suffering from IBS typically present with the following⁸:

• Abdominal pain and cramping
• Bloating and passing of gas
• Constipation
• Diarrhea

Although patients may be classified as either IBS-C or IBS-D, over half of the patients are likely to change the subtype over a 1-year period⁹, and hence presentations and symptoms may change for these patients, with some presenting with alternating constipation and diarrhea.

Some patients may also experience mucus in their stools and fatigue/ tiredness.

How to manage irritable bowel syndrome?

Several international guidelines have outlined the management of IBS depending on the subtypes of IBS. Such guidelines consist of both lifestyle advice and the different medications that can be used to manage and treat IBS. For this section, we will refer to guidelines on IBS management from both the American College of Gastroenterology (ACG)¹⁰, as well as the British Society of Gastroenterology (BSG)¹¹.

Lifestyle – Fiber

Both guidelines have outlined the importance of using soluble fiber (and not insoluble fiber) as an effective treatment for the global symptoms of IBS. The guidelines have both recommended the use of soluble fiber for managing IBS symptoms after reviewing results from multiple clinical trials and found that soluble fiber intake was able to relief IBS symptoms significantly as compared to placebo. Insoluble fiber, on the other hand, may exacerbate symptoms such as bloating and pain.

Soluble fiber did not show any significant side effects as well, and hence the guidelines have provided a strong recommendation to the use soluble fiber as a reasonable first-line therapy in managing patients with IBS symptoms.

Other lifestyle changes

Frequent exercise may be able to help manage IBS as well, as recommended by the BSG guidelines. A reasonable 2^nd-line management option can include the use of a low FODMAP diet. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, polyols. These substances lead to increase fermentation in the colon, producing short-chain fatty acids and gases, triggering symptoms of IBS in certain patients. Although potentially a viable option for the treatment of IBS, these guidelines believe that the complexity of implementing this diet means that patients should be under the supervision of trained dieticians.

Medications

If your condition is not sufficiently managed by lifestyle changes, your doctor may consider the use of certain medications, depending on the subtype of your IBS and severity of your IBS symptoms. The types of medications include:

• Loperamide
• Lubiprostone
• Linaclotide, plecanatide
• Tegaserod
• Rifaximin
• Alosetron (for women)
• Eluxadoline
• Tricyclic antidepressants (e.g., amitriptyline, nortriptyline, imipramine)
• Clidinium with chlordiazepoxide

Your doctor will decide which is the best treatment option for your IBS condition.

Conclusion

Irritable bowel syndrome (IBS) is a relatively common chronic gastrointestinal condition that affects about 10% of people worldwide. Typical symptoms include abdominal pain and constipation and/or diarrhea, which will determine the subtype of IBS, although the presentation may vary as the disease progresses. One of the 1^st-line treatment of IBS recommended by international guidelines such as the ACG and BSG include the use of soluble fiber, which is especially helpful for patients who suffer from constipation symptoms from IBS. Other lifestyle changes also include regular exercise and possible use of low FODMAPs diet.

Article is written in conjunction with IBS Month every April.

References

1. Canavan C, West J, Card T. The epidemiology of irritable bowel syndrome. Clin Epidemiol. 2014;6:71-80. Available on: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3921083/
2. Palsson OS, Whitehead W, Törnblom H, et al. Prevalence of Rome IV Functional Bowel Disorders Among Adults in the United States, Canada, and the United Kingdom. Gastroenterology. 2020 Apr;158(5):1262-1273.e3. Available on: https://pubmed.ncbi.nlm.nih.gov/31917991/
3. What is IBS-M? 2021 Apr. Available on: https://www.webmd.com/ibs/what-is-ibs-m
4. National Health System (NHS), United Kingdom (UK). Getting diagnosed: Irritable bowel syndrome (IBS). 2021 February. Available on: https://www.nhs.uk/conditions/irritable-bowel-syndrome-ibs/getting-diagnosed/
5. Lacy BE, Mearin F, Chang L, et al. Bowel disorders. Gastroenterology. 2016;150:1393–407.
6. National Institutes of Health (NIH), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Symptoms & Causes of Irritable Bowel Syndrome. 2017 November. Available on: https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/symptoms-causes
7. Cleveland Clinic. Irritable Bowel Syndrome (IBS). 2020 April. Available on: https://my.clevelandclinic.org/health/diseases/4342-irritable-bowel-syndrome-ibs
8. Everything You Want to Know About IBS. 2017 July. Available on: https://www.healthline.com/health/irritable-bowel-syndrome
9. Palsson OS, Baggish JS, Turner MJ, Whitehead WE. IBS patients show frequent fluctuations between loose/watery and hard/lumpy stools: implications for treatment. Am J Gastroenterol. 2012 Feb;107(2):286-95. Available on: https://pubmed.ncbi.nlm.nih.gov/22068664/
10. Lacy BE, Pimentel M, Brenner DM, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. Am J Gastroenterol. 2021 Jan 1;116(1):17-44. Available on: https://journals.lww.com/ajg/Fulltext/2021/01000/ACG_Clinical_Guideline__Management_of_Irritable.11.aspx
11. Vasant DH, Paine PA, Black CJ, et al. British Society of Gastroenterology guidelines on the management of irritable bowel syndrome. 2021;70:1214-1240. Available on: https://gut.bmj.com/content/70/7/1214