What does IBS really stand for?

Content
1. Definition of Irritable Bowel Syndrome
1.1 Rom-IV-Criteria
1.2 The Four Main Types of IBS According to Rome IV
2. Causes of Irritable Bowel Syndrome
2.1 Altered Gut Microbiome
2.2 Psychological Stress
2.3 Impaired or Sensitive Gut Barrier
3. IBS and SIBO
4. Treatment Options for IBS

1. Definition of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) refers to a condition characterized by various digestive tract symptoms. More precisely, IBS is a chronic dysfunction of the intestines, diagnosed as a diagnosis of exclusion. This means that any other digestive tract diseases (gastrointestinal disorders) must be ruled out as the cause of the symptoms. This already highlights how vaguely IBS is defined.
The main features of IBS are pain or discomfort in the abdominal area, changes in stool frequency and quality, as well as bloating and feelings of fullness.
IBS is relatively common, with women being affected more often than men (1).

1.1 Rom-IV-Criteria

The Rome IV criteria were developed to distinguish IBS more precisely from other functional gastrointestinal disorders. They consider not only the frequency and duration of symptoms but also their impact on the patient’s quality of life. Since IBS is a chronic and often distressing condition, an accurate diagnosis is essential to initiate appropriate treatment and alleviate symptoms effectively.
The Rome IV criteria were developed to distinguish IBS more precisely from other functional gastrointestinal disorders. They consider not only the frequency and duration of symptoms but also their impact on the patient’s quality of life. Since IBS is a chronic and often distressing condition, an accurate diagnosis is essential to initiate appropriate treatment and alleviate symptoms effectively.

Compared to the previous Rome III classification, the Rome IV criteria place a stronger emphasis on pain as the primary diagnostic criterion, ensuring a clearer distinction from other functional bowel disorders. Additionally, the role of psychological factors, such as stress and anxiety, in the development and persistence of IBS is more strongly recognized. The Rome IV criteria not only support clinical diagnosis but also serve as a foundation for research by ensuring a uniform definition of IBS, which improves the comparability of scientific studies.

1.2 The Four Main Types of IBS According to Rome IV

IBS can be classified into four main types (2):

• IBS with predominant constipation: IBS-C,
• IBS with predominant diarrhea: IBS-D,
• IBS with mixed bowel habits: IBS-M and
• IBS unclassified: IBS-U

2. Causes of Irritable Bowel Syndrome

For a long time, the cause of IBS was unclear, and the condition was simply classified as a psychosomatic disorder. However, recent research—particularly in the field of the gut microbiome—has identified additional possible causes. While the exact causes of IBS remain unknown, it is believed that a combination of factors contributes to its development, including changes in the gut microbiome, stress, altered gut-brain communication (gut-brain axis), leaky gut (a compromised gut barrier), inflammation of the intestinal lining, increased gut sensitivity, and past infections.

2.1 Altered Gut Microbiome

IBS is associated with changes in the gut microbiome and metabolome (1,3). Prior antibiotic use has been suggested as a trigger for IBS (1), and intestinal inflammation has also been linked to its development (1).

2.2 Psychological Stress

Psychological stress, anxiety disorders, and depression are also thought to contribute to the onset and persistence of IBS (1). The gut-brain axis appears to play a particularly important role in IBS, as it can be altered at all levels, including the organic, cellular, molecular, and genetic levels (1,4).

2.3 Impaired or Sensitive Gut Barrier

A damaged gut barrier can lead to abdominal pain. Increased intestinal permeability (leaky gut) allows undigested food particles, gut bacteria, and ingested microorganisms to pass through the intestinal lining and enter the bloodstream. This can activate the immune system, triggering inflammatory responses, which may further damage the gut lining and worsen its integrity, creating a vicious cycle.

3. IBS and SIBO

A growing body of research suggests a link between IBS and SIBO (small intestinal bacterial overgrowth). Studies indicate that the prevalence of SIBO is higher in IBS patients (5,6).

4. Treatment Options for IBS

IBS can significantly impact a person’s quality of life and daily activities. The primary goal of treatment is to alleviate symptoms and improve overall well-being.
Treatment approaches include dietary adjustments, optimizing sleep hygiene, restoring gut microbiome balance, possible medication use, stress management, and regular physical activity such as yoga, along with lifestyle modifications that integrate all these elements.
A low-FODMAP diet or identifying trigger foods (e.g., gluten, lactose) can help reduce symptoms. Depending on the IBS subtype, antispasmodic medications, probiotics, fiber supplements, or treatments for diarrhea/constipation may be beneficial. Relaxation techniques, cognitive behavioral therapy (CBT), and mindfulness training can assist in stress management. Regular exercise and good sleep hygiene are also essential parts of an IBS treatment plan. A doctor can help identify the underlying causes and recommend an appropriate treatment strategy to reduce symptoms and improve comfort.

References

1. Update S3-Leitlinie Reizdarmsyndrom: Definition, Pathophysiologie, Diagnostik und Therapie. Gemeinsame Leitlinie der Deutschen Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten (DGVS) und der Deutschen Gesellschaft für Neurogastroenterologie und Motilität (DGNM), 2021, https://www.dgvs.de/wp-content/uploads/2022/02/ZfG_Leitlinie-LL-Reizdarmsyndrom_08.02.22.pdf; zuletzt geprüft 30.04.2023.
2. Rome IV Criteria – Rome Foundation (theromefoundation.org); last checked 30.04.2023.
3. Vich Vila A, Imhann F, Collij V, Jankipersadsing SA, Gurry T, Mujagic Z, Kurilshikov A, Bonder MJ, Jiang X, Tigchelaar EF, Dekens J, Peters V, Voskuil MD, Visschedijk MC, van Dullemen HM, Keszthelyi D, Swertz MA, Franke L, Alberts R, Festen EAM, Dijkstra G, Masclee AAM, Hofker MH, Xavier RJ, Alm EJ, Fu J, Wijmenga C, Jonkers DMAE, Zhernakova A, Weersma RK. Gut microbiota composition and functional changes in inflammatory bowel disease and irritable bowel syndrome. Sci Transl Med. 2018 Dec 19;10(472):eaap8914. doi: 10.1126/scitranslmed.aap8914. PMID: 30567928.
4. Ford AC, Sperber AD, Corsetti M, Camilleri M. Irritable bowel syndrome. Lancet. 2020 Nov 21;396(10263):1675-1688. doi: 10.1016/S0140-6736(20)31548-8. Epub 2020 Oct 10. PMID: 33049223.
5. Takakura W, Pimentel M. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome – An Update. Front Psychiatry. 2020 Jul 10;11:664. doi: 10.3389/fpsyt.2020.00664. PMID: 32754068; PMCID: PMC7366247.
6. Ghoshal UC, Shukla R, Ghoshal U. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy. Gut Liver. 2017 Mar 15;11(2):196-208. doi: 10.5009/gnl16126. PMID: 28274108; PMCID: PMC5347643.
7. Rome IV Criteria; Rome IV Criteria – Rome Foundation; last checked 23.02.2015