Could SIBO or Thyroid Issues Be the Root Causes of Your Constipation?
Do you often feel bloated, uncomfortable, and struggling with constipation? You're not alone. Millions worldwide grapple with these issues daily, often without realizing the root causes.
Constipation is a common health issue, and many people labeled with IBS (Irritable Bowel Syndrome) are told to accept this symptom as their fate. Still, constipation can be a sign of dysfunction or imbalance, and it can be disruptive and uncomfortable, affecting your overall health.
That's why I've created this essential blog post—to help you uncover the common hidden causes of constipation and take the first step towards reclaiming your health. From Small Intestinal Bacterial Overgrowth (SIBO) to thyroid issues, explore how these health conditions might be the unexpected culprits behind your discomfort.
Let's discover how to manage these conditions to relieve constipation symptoms effectively. By understanding the root causes, you can make targeted diet and lifestyle changes that provide lasting relief.
What does constipation mean?
Constipation is a digestive condition characterized by infrequent bowel movements, meaning that you have three or fewer bowel movements per WEEK.
But even if you go to the toilet daily, you can still be constipated. If you strain on the toilet, have difficulty passing stools, or your stool comes out in pellets (and not smoothly and in a long shape) and is hard and lumpy, there is a high chance of being constipated.
Need help identifying your stool type? Check out the Bristol Stool Chart for more information. Types 1 - 2 indicate constipation, while type 3 is considered as tending towards constipation.
But constipation may also be accompanied by other symptoms such as abdominal discomfort, bloating, gassiness, or a feeling of incomplete evacuation. Some people may also experience reflux symptoms, as gas and bloating push up acid to the esophagus. (1)
Constipation is a common digestive problem affecting around 16% of the general population, and women are more likely to suffer from constipation than men. (2)
Constipation may be acute or chronic, lasting many months or even years.
Why should you care about constipation?
Because your bowels are designed to eliminate toxins and waste.
When you have slow transit in the intestines, toxins, and waste get stuck in your body too long, reabsorbed into the bloodstream, and waste putrefies in the colon, feeding pathogenic bacteria and fuelling inflammation. This process can put extra pressure on the liver to work hard on elimination. Consequently, you may experience additional symptoms like hormonal imbalances, skin problems (like acne), brain fog, and headaches.
3 Possible Causes of Constipation (3)
1. Poor lifestyle choices (4)
- Dehydration: Inadequate fluid intake is one of the most common causes of constipation. When dehydrated, your body draws water from stools to maintain hydration, making them harder and more difficult to pass. Excess caffeine or alcohol intake can also lead to dehydration.
- Lack or excess dietary fiber intake: A diet low in fiber can contribute to constipation. Fiber adds bulk to your stool, helping it move more efficiently through your digestive tract. But in some cases, eating too much raw foods, veggies, and fiber can contribute to slow digestion, especially in people with SIBO.
- Sedentary Lifestyle: Physical inactivity can slow your digestive system, leading to constipation. Regular exercise can stimulate intestinal muscles, aiding digestion.
- Ignoring the urge to defecate.
2. Small Intestinal Bacterial Overgrowth (SIBO):
SIBO is a condition where an excessive amount or abnormal type of bacteria are present in the small intestine, where their numbers should be relatively low compared to the large intestine. (The large intestine house the highest number of bacteria). These bacteria in the wrong place can interfere with normal digestion and absorption of food by fermenting carbohydrates and fibers and creating byproducts, like gases, leading to symptoms like:
- changed bowel movements: constipation and/or diarrhea,
- constant bloating, gassiness,
- abdominal pain,
- nausea,
- fatigue, brain fog,
- skin issues (acne, Rosacea),
- joint and muscle pain, etc. (5)
One of the primary reasons revolves around the role of the Migrating Motor Complex (MMC). The MMC is a pattern of electrical activity that occurs in the smooth muscle of the gastrointestinal tract during the periods between meals. It's often referred to as the "housekeeper" of our gut because its function is to sweep residual undigested material through the digestive tract. The MMC operates in a cyclical manner, approximately every 90-120 minutes during fasting periods. (This is one of the reasons why constant snacking is a bad idea with SIBO!)
When the MMC is functioning correctly, it helps control the bacterial population in the small intestine by regularly clearing it out, pushing bacteria into the large intestine, and preventing any significant accumulation. However, certain conditions like stress, medications (especially opioids), certain diseases (like Scleroderma), or other underlying causes (>>check out the SIBO Root cause Masterclass for more information) can disrupt the MMC's functioning, leading to a slowdown or stoppage of this cleaning wave. This disruption can allow bacteria to multiply excessively in the small intestine, leading to SIBO. (6)
Once SIBO has been established, the overgrown bacteria can interfere with normal digestion and nutrient absorption. Moreover, they can produce large amounts of gas (methane, hydrogen, hydrogen sulfide) as they ferment the food that you eat.
Particularly, methane-producing archaea have been linked to constipation, defining it as Intestinal Methane Overgrowth (IMO) since they are technically not bacteria. They have been identified as Methanobrevibacter smithii in the gut and stool tests.
Methane gas can slow down the transit time, leading to constipation. It's a bit of a vicious cycle - the slower transit time allows more time for bacteria to ferment carbohydrates, leading to more methane production and further slowing down gut motility. (7)
3. Thyroid dysfunction
The thyroid gland, a small butterfly-shaped organ located in your neck, plays a pivotal role in your body's metabolic functions. It produces vital hormones – triiodothyronine (T3) and thyroxine (T4) – that regulate metabolism, influencing how your body uses energy and processes food. When the thyroid is underactive, a condition known as hypothyroidism, it can significantly affect your digestive health, particularly leading to constipation.
In individuals with hypothyroidism, the production of thyroid hormones is insufficient, resulting in a slowdown of metabolic processes, including gut motility - the speed at which food moves through the digestive tract. With reduced gut motility, the digestive tract takes longer to process and move stools, often resulting in constipation. (8)
Hypothyroidism and SIBO
The connection between hypothyroidism and SIBO comes back to the gut motility issue. The slowed gut motility in hypothyroid individuals can disrupt the functioning of the Migrating Motor Complex (MMC), the mechanism that sweeps residual undigested material and bacteria through the digestive tract.
As discussed in the previous section, proper MMC function is crucial to preventing bacterial overgrowth in the small intestine. When MMC function is compromised, as in hypothyroidism, it can result in an accumulation of bacteria in the small intestine, leading to SIBO. (9)
Thyroid, Liver Function, and Constipation
The thyroid also has a crucial connection with liver function. The liver is the primary site where T4 is converted into its active form, T3. In cases of hypothyroidism, this conversion process can be compromised, exacerbating the symptoms of low thyroid function. Furthermore, the liver plays a vital role in digestion by producing bile, which helps break down fats. If liver function is affected due to impaired thyroid activity, it can lead to constipation. (10)
Low Stomach Acid and Hypothyroidism
Another digestive issue linked to hypothyroidism is low stomach acid or hypochlorhydria. Studies estimate that around 30% of people with hypothyroidism have low stomach acid. (11) Adequate stomach acid is necessary for breaking down food, absorbing nutrients, and preventing harmful bacteria from entering the gut. (12) Individuals with hypothyroidism often produce less stomach acid, slowing digestion and contributing to constipation. (13)
Other contributing factors
The list is not complete, as there can be many different reasons (4) for being constipated. Here are some other examples:
- Food allergy/intolerance
- Stress, anxiety, depression
- Dysbiosis (imbalance between the beneficial and pathogenic gut bugs in the gut), including bacterial, parasitic, and fungal overgrowth
- Sluggish liver function
- Heavy metal toxicity
- Lack of stomach acid
- Nutrient deficiencies
- Metabolic disorders (Diabetes)
- Structural problems
- Side effects of medications (anti-histamines, opioids, NSAIDs, antacids, PPI's, antidepressants, etc.), overuse of laxatives
- Neurological disorders (Parkinson's, Alzheimer's, Multiple Sclerosis, etc.)
- History of eating disorders (Anorexia Nervosa or Bulimia)
How to Relieve Constipation Naturally
Understanding the potential causes of constipation can provide effective strategies for overcoming this common digestive issue.
The first step for many people leads through conventional medicine. Doctors may suggest colonoscopy or other testing options based on the symptoms and health history, but unfortunately, I commonly see that many patients end up with laxatives in their hands.
Laxatives have many forms, but they will just treat the symptom, serving as a band-aid approach rather than a long-term solution. Not to mention that laxatives may also come with side effects if used long-term. (14)
Taking a holistic approach could be a better strategy for long-term resolution. Functional Medicine and Nutrition focus on the root causes and treating the body as a whole. Specific functional testing options like gut microbiome testing, SIBO breath test, mineral testing, complete thyroid panel, hormonal testing, etc., can provide a clearer picture of the imbalances happening on a deeper level.
As we've discussed, poor lifestyle choices, Small Intestinal Bacterial Overgrowth (SIBO), and thyroid dysfunction, particularly hypothyroidism, can all contribute to constipation.
Here are some natural strategies to help manage constipation, taking into account these three primary causes:
Improve Lifestyle Choices
Dietary guidelines (15):
- Increase Fiber Intake: Fiber adds bulk to your stools, making them easier to pass. Include fiber-rich foods such as whole grains, fruits, vegetables, and legumes in your diet. Psyllium, oat, and chia bran can also be a great addition (careful if you have SIBO!). Fiber intake should be increased gradually to at least 30 g/day for men and 25 g/day for women.
- Decrease sugar, alcohol, and processed foods that have a negative impact on the gut microbiome
- Bitter foods like radicchio, dandelion greens, arugula, artichokes, and endive can help stimulate digestion
- Ginger is excellent for stimulating gastric emptying and gut motility
- Stay hydrated: Adequate hydration can prevent stools from becoming hard and difficult to pass. Aim to drink at least 8 cups of water daily, especially if consuming more fiber. Despite drinking enough water, our cells can still be dehydrated and miss essential minerals like magnesium, potassium, sodium, etc. Adding a pinch of Celtic sea or Himalayan salt can be a great way to replenish minerals for the body.
Other lifestyle changes:
- Regular Exercise: Physical activity stimulates your digestive system and can help maintain regular bowel movements. Even light activities like walking, yoga, or Qigong can be beneficial. (16)
- Manage Stress: Chronic stress can exacerbate digestive and thyroid symptoms. Stress management techniques such as meditation, yoga, and deep breathing can be helpful.
Address SIBO to relieve constipation
If you suspect you have SIBO, getting a diagnosis from a healthcare provider is essential. They can order a SIBO Breath test to determine the types of SIBO and the amount of overgrowth you may have.
Addressing SIBO and restoring the normal functioning of the MMC is crucial in resolving constipation linked to this condition.
Dietary modifications, like temporarily limiting fermentable foods: certain carbohydrates, known as FODMAPs, can exacerbate SIBO symptoms. A low-FODMAP diet might be recommended for SIBO-related constipation and bloating. While the low-FODMAP diet can help MANAGE THE SYMPTOMS in the short term, it will not solve the underlying reasons that are possibly causing your SIBO! (17)
Mindful Eating is crucial for overall digestion: eating slowly and chewing your food thoroughly can improve digestion and absorption, reducing the workload on your small intestine. (There is a reason why you have teeth and saliva in your mouth.)
Since MMC is often dysfunctional, prokinetic agents (medications that help increase the motor activity of the gastrointestinal tract) and targeted antibiotic or antimicrobial therapy are common strategies used in treating SIBO. (18)
One particular probiotic strain: Lactobacillus reuteri (DSM 17938), has been shown to decrease methane production and chronic constipation significantly. (19)
Manage Thyroid Dysfunction
Proper testing for thyroid dysfunctions: If you suspect you may have thyroid dysfunction, asking for a FULL thyroid panel is essential. The full panel should include TSH, free T4, free T3, Thyroid Peroxidase Antibodies (TPO Ab), and reverse T3.
Conventional medicine typically considers the TSH level normal between the range of 0.5 - 4.5 mIU/L. However, in functional medicine, a narrower range is preferred for optimal TSH function: 1.0 - 2.5 mlU/L.
Follow a nutrient-rich diet: Certain nutrients, including iodine, selenium, magnesium, and zinc, are essential for thyroid health.
Here are some examples of foods rich in these essential minerals (20):
- Iodine:
- Sea vegetables like kelp, nori, and kombu
- Fish and seafood, especially cod and shrimp
- Dairy products like milk, cheese, and yogurt
- Selenium:
- Brazil nuts (they are exceptionally high in selenium)
- Seafood, poultry, and eggs
- Whole grains, like brown rice and oats
- Magnesium:
- Green leafy vegetables, whole grains (quinoa and brown rice)
- Nuts and seeds, like almonds and flaxseeds
- Legumes, including black beans and lentils
- Dark chocolate
- Zinc:
- Meat, particularly beef, and lamb
- Shellfish, especially oysters, are a top source of zinc
- Legumes like chickpeas, lentils, and beans
- Seeds, such as pumpkin seeds and sesame seeds, and nuts, including cashews and almonds
The bottom line
In conclusion, while constipation can be a disruptive and uncomfortable issue, understanding its causes can guide effective strategies to manage and overcome it. Improving lifestyle choices, addressing underlying conditions like SIBO or thyroid dysfunction, and maintaining a healthy diet can significantly improve digestive health. Your journey to improved gut health and relief from constipation starts with understanding and addressing these key factors.
This post is only for informational purposes and is not meant to diagnose, treat or cure any disease. I recommend consulting with your healthcare practitioner always before trying any treatment or dietary changes.
Bristol Stool Chart: Chumpitazi, B. P., Self, M. M., Czyzewski, D. I., Cejka, S., Swank, P. R., & Shulman, R. J. (2016). Bristol Stool Form Scale reliability and agreement decreases when determining Rome III stool form designations. Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society, 28(3), 443–448. https://doi.org/10.1111/nmo.12738
Further references:
- Symptoms & Causes of Constipation. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/digestive-diseases/constipation/symptoms-causes
- Forootan, M., Bagheri, N., & Darvishi, M. (2018). Chronic constipation: A review of literature. Medicine, 97(20), e10631. https://doi.org/10.1097/MD.0000000000010631
- Diaz S, Bittar K, Mendez MD. Constipation. [Updated 2023 Jan 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513291
- Fathallah, N., Bouchard, D., & de Parades, V. (2017). Les règles hygiéno-diététiques dans la constipation chronique de l’adulte : du fantasme à la réalité… [Diet and lifestyle rules in chronic constipation in adults: From fantasy to reality…]. Presse medicale (Paris, France : 1983), 46(1), 23–30. https://doi.org/10.1016/j.lpm.2016.03.019
- Achufusi, T. G. O., Sharma, A., Zamora, E. A., & Manocha, D. (2020). Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods. Cureus, 12(6), e8860. https://doi.org/10.7759/cureus.8860
- Deloose, E., Janssen, P., Depoortere, I., & Tack, J. (2012). The migrating motor complex: control mechanisms and its role in health and disease. Nature reviews. Gastroenterology & hepatology, 9(5), 271–285. https://doi.org/10.1038/nrgastro.2012.57
- Triantafyllou, K., Chang, C., & Pimentel, M. (2014). Methanogens, methane and gastrointestinal motility. Journal of neurogastroenterology and motility, 20(1), 31–40. https://doi.org/10.5056/jnm.2014.20.1.31
- Müller-Lissner, S. A., Kamm, M. A., Scarpignato, C., & Wald, A. (2005). Myths and misconceptions about chronic constipation. The American journal of gastroenterology, 100(1), 232–242. doi.org/10.1111/j.1572-0241.2005.40885.x
- Patil A. D. (2014). Link between hypothyroidism and small intestinal bacterial overgrowth. Indian journal of endocrinology and metabolism, 18(3), 307–309. https://doi.org/10.4103/2230-8210.131155
- Portincasa, P., Di Ciaula, A., Wang, H. H., Palasciano, G., van Erpecum, K. J., Moschetta, A., & Wang, D. Q. (2008). Coordinate regulation of gallbladder motor function in the gut-liver axis. Hepatology (Baltimore, Md.), 47(6), 2112–2126. https://doi.org/10.1002/hep.22204
- Cellini, M., Santaguida, M. G., Virili, C., Capriello, S., Brusca, N., Gargano, L., & Centanni, M. (2017). Hashimoto's Thyroiditis and Autoimmune Gastritis. Frontiers in endocrinology, 8, 92. https://doi.org/10.3389/fendo.2017.00092
- org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. How does the stomach work? 2009 Dec 31 [Updated 2016 Aug 21]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279304/
- Ebert E. C. (2010). The thyroid and the gut. Journal of clinical gastroenterology, 44(6), 402–406. https://doi.org/10.1097/MCG.0b013e3181d6bc3e
- Khan, S., & Khan, S. U. (2020). Adverse drug event of hypokalaemia-induced cardiotoxicity secondary to the use of laxatives: A systematic review of case reports. Journal of Clinical Pharmacy and Therapeutics, 45(5), 927-936. https://doi.org/10.1111/jcpt.13204
- Bae S. H. (2014). Diets for constipation. Pediatric gastroenterology, hepatology & nutrition, 17(4), 203–208. https://doi.org/10.5223/pghn.2014.17.4.203
- Gao, R., Tao, Y., Zhou, C., Li, J., Wang, X., Chen, L., Li, F., & Guo, L. (2019). Exercise therapy in patients with constipation: a systematic review and meta-analysis of randomized controlled trials. Scandinavian journal of gastroenterology, 54(2), 169–177. https://doi.org/10.1080/00365521.2019.1568544
- Barrett J. S. (2017). How to institute the low-FODMAP diet. Journal of gastroenterology and hepatology, 32 Suppl 1, 8–10. https://doi.org/10.1111/jgh.13686
- Sorathia SJ, Chippa V, Rivas JM. Small Intestinal Bacterial Overgrowth. [Updated 2022 Oct 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK546634/
- Ojetti, V., Petruzziello, C., Migneco, A., Gnarra, M., Gasbarrini, A., & Franceschi, F. (2017). Effect of Lactobacillus reuteri (DSM 17938) on methane production in patients affected by functional constipation: a retrospective study. European review for medical and pharmacological sciences, 21(7), 1702–1708.
- Dahiya, V., Vasudeva, N., Sharma, S., & Kumar, A. (2022). Role of Dietary Supplements in Thyroid Diseases. Endocrine, metabolic & immune disorders drug targets, 22(10), 985–996. https://doi.org/10.2174/1871530322666220419125131
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