Constipation in SIBO and What to Do About It

Content

1. Definition of Constipation
1.1 Types of Constipation
1.2 Chronic Constipation
2. Causes of Constipation
3. Constipation in SIBO
3.1 Methane as a Cause of Constipation
4. . Constipation in Irritable Bowel Syndrome
5. What to do about Constipation?
5.1 Laxatives
5.2 Fibers
5.3 Exercise and Yoga

Constipation is one of the classic symptoms of SIBO. But what are the causes and what can be done about it?

1. Definition of Constipation

Constipation refers to infrequent bowel movements, hard stool consistency, and/or insufficient stool volume. During bowel passage, water is drawn from the stool because our body can make use of this water. However, if the stool stays in the intestines for too long, for example due to reduced gut motility, it hardens more and more, which ultimately makes it harder to pass. This is noticeable through the need for excessive straining during bowel movements.
How often people have bowel movements varies from person to person. A bowel movement less than three times a week is considered too infrequent and thus an indication of constipation.

1.1 Types of Constipation

There are different types of constipation: In STC (slow-transit constipation), there is irregular bowel movement, leading to the stool staying in the intestines for a longer time. In NTC (normal-transit constipation), stool passage through the colon is normal, but patients have difficulty passing the stool. (1)

1.2 Chronic Constipation

Chronic constipation is defined by at least two of the following criteria (2):
Lumpy or hard stool (Bristol stool forms 1-2) > in more than 25% of bowel movements.
• Excessive straining > in more than 25% of bowel movements.
• Subjective incomplete emptying > in more than 25% of bowel movements.
• Subjective obstruction > in more than 25% of bowel movements.
• Manual maneuvers to facilitate defecation > in more than 25% of bowel movements. < Less than three spontaneous bowel movements per week.
This form of constipation represents a distinct disease entity and is diagnosed only when no criteria for irritable bowel syndrome are met. (2)

2. Causes of Constipation

The causes of constipation can be many and varied. These include lack of exercise, insufficient fluid intake, dietary errors (especially a diet that is too low in fiber) or organic causes.

3. Constipation in SIBO

In Small Intestinal Bacterial Overgrowth (SIBO), constipation can occur as a symptom. SIBO refers to the pathological overgrowth of bacteria in the small intestine. Under normal conditions, the small intestine, unlike the large intestine, is sparsely populated with bacteria. Due to the excessive bacterial growth in the wrong place, the small intestine becomes overwhelmed. The small intestine cannot handle the gases and toxins produced by the bacteria. The consequences include symptoms such as abdominal pain, bloating, diarrhea, constipation, belching, fullness, and heartburn. Some patients also report fatigue and concentration difficulties. There are three main forms of SIBO, categorized by the predominant gases produced: hydrogen (_H2), methane (_CH4), and hydrogen sulfide (_H2S). Constipation particularly occurs with methane-SIBO. The presence of SIBO and its classification into the different main forms can be determined through a breath test.

3.1 Methane as a Cause of Constipation

In a methane SIBO, the presence of archaea predominates. As archaea are not bacteria, the term SIBO (bacterial overgrowth) is actually not quite correct here. Nevertheless, this form of small intestinal overgrowth is also classified as SIBO.
The gas methane is produced as a metabolic end product of the archaea and has an effect on the intestine. Methane can reduce the intestinal transit time (4,5). This in turn favors the development of constipation.

4. . Constipation in Irritable Bowel Syndrome

Another cause of constipation can be found in irritable bowel syndrome. In addition to the diarrhoea-predominant irritable bowel syndrome type RDS-D, there are also the types RDS-O (obstipation-predominant), RDS-A (alternating diarrhoea and constipation) and RDS-M (mixed stool behaviour within one day). According to the current irritable bowel syndrome guideline, the RDS-O type accounts for 1/3 of all cases. (3)
In addition to constipation, other symptoms of irritable bowel syndrome can include bloating and flatulence.

5. What to do about Constipation?

5.1 Laxatives

To combat constipation or prevent its development, there are several options. Medically, the use of laxatives is recommended. However, there are also non-medical approaches to managing constipation.

5.2 Fibers

Dietary fiber is very important here (6). However, when increasing fiber intake, it is important to start with low doses and increase them slowly (7). If too much fiber is consumed too quickly, this can lead to discomfort, as neither the intestines nor the microbiota know how to deal with these quantities.
The stool-regulating effect of dietary fiber can be further enhanced by an adequate intake of fluids (8).

5.3 Exercise and Yoga

In addition to medications and dietary adjustments, exercise and yoga can help with constipation, especially in cases of SIBO and IBS (9,10). Exercise supports gut motility, improves circulation, and contributes to a healthy lifestyle.

References

1. Diaz S, Bittar K, Hashmi MF, Mendez MD. Constipation. 2023 Nov 12. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan–. PMID: 30020663.
2. Aktualisierte S2k-Leitlinie chronische Obstipation der Deutschen Gesellschaft für Gastroenterologie, Verdauungs- und Stoffwechselkrankheiten (DGVS) und der Deutsche Gesellschaft für Neurogastroenterologie & Motilität (DGNM); April 2022; https://register.awmf.org/assets/guidelines/021-019l_S2k_Chronische_Obstipation_2022-04_01.pdf; latest check 29.04.2024
3. 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); Juni 2021; https://register.awmf.org/assets/guidelines/021-016l_S3_Definition-Pathophysiologie-Diagnostik-Therapie-Reizdarmsyndroms_2022-02.pdf; latest check 29.04.2024
4. Pimentel, Mark; Gunsalus, Robert P; Rao, Satish Sc; Zhang, Husen; Methanogens in Human Health and Disease; The American Journal of Gastroenterology Supplements; New York; 2012
5. Pimentel M, Lin HC, Enayati P, van den Burg B, Lee HR, Chen JH, Park S, Kong Y, Conklin J. Methane, a gas produced by enteric bacteria, slows intestinal transit and augments small intestinal contractile activity. Am J Physiol Gastrointest Liver Physiol. 2006 Jun;290(6):G1089-95. doi: 10.1152/ajpgi.00574.2004. Epub 2005 Nov 17. PMID: 16293652.
6. Manz M, Meier R. Pharmakologische Therapie von Transitstörungen [Pharmacologic treatments of transit disorders]. Ther Umsch. 2007 Apr;64(4):227-32. German. doi: 10.1024/0040-5930.64.4.227. PMID: 17663210.
7. Zuckerman MJ. The role of fiber in the treatment of irritable bowel syndrome: therapeutic recommendations. J Clin Gastroenterol. 2006 Feb;40(2):104-8. doi: 10.1097/01.mcg.0000196405.15110.bb. PMID: 16394869.
8. Anti M, Pignataro G, Armuzzi A, Valenti A, Iascone E, Marmo R, Lamazza A, Pretaroli AR, Pace V, Leo P, Castelli A, Gasbarrini G. Water supplementation enhances the effect of high-fiber diet on stool frequency and laxative consumption in adult patients with functional constipation. Hepatogastroenterology. 1998 May-Jun;45(21):727-32. PMID: 9684123.
9. Evans S, Lung KC, Seidman LC, Sternlieb B, Zeltzer LK, Tsao JC. Iyengar yoga for adolescents and young adults with irritable bowel syndrome. J Pediatr Gastroenterol Nutr. 2014 Aug;59(2):244-53. doi: 10.1097/MPG.0000000000000366. PMID: 25025601; PMCID: PMC4146428.
10. Johannesson E, Ringström G, Abrahamsson H, Sadik R. Intervention to increase physical activity in irritable bowel syndrome shows long-term positive effects. World J Gastroenterol. 2015 Jan 14;21(2):600-8. doi: 10.3748/wjg.v21.i2.600. PMID: 25593485; PMCID: PMC4294172.