Understanding Constipation: What’s Really Happening in Your Gut

Constipation is something most of us will experience at some point. In fact, around 10–15% of adults worldwide live with it at any given time and is often a sign that your digestion isn’t working as smoothly as it could.

What’s Going On Inside?

Your gut is designed to move things along. The walls of your intestines contract gently and rhythmically to push waste through which is called motility, meaning movement. When this slows down, stool spends longer in the colon. The longer it stays there, the more water is reabsorbed, leaving stool hard, dry, and difficult to pass.

Doctors usually describe constipation as fewer than three bowel movements per week, or straining to pass stool even when you feel the urge.

The Different Types of Constipation

Not all constipation is the same, and understanding the type can make a difference when it comes to support options.

• Functional constipation – the most common type, where bowel movements are infrequent or difficult but there’s no underlying disease. This is also the form most often studied with supplements.

• Slow-transit constipation – here, the colon moves waste along more slowly than usual.

There are also pelvic floor dysfunction (when the muscles used to pass stool don’t coordinate properly) and secondary constipation (caused by another condition such as diabetes, thyroid problems, or side effects of medicines) but these require medical management first.

Why Does Constipation Happen?

Constipation is often the result of a combination of factors, including:

• Travel or changes in routine – disrupting your body’s rhythm.

• Stress – the gut and brain are closely linked, so emotional stress can affect digestion

• Dehydration – not enough fluid makes stool firmer.

• Low fibre intake – fibre bulks and softens stool.

• Lack of exercise – sitting for long periods slows gut movement.

• Medications – iron tablets, and some antidepressants can reduce gut motility.
  
  

Can Synbiotics or Probiotics Help?

When it comes to easing constipation, synbiotics may offer particular benefits. Synbiotics combine probiotics with prebiotics, the fibres that act as food for these bacteria.

One of the best-studied prebiotics is fructo-oligosaccharides (FOS). FOS is a naturally occurring fibre found in foods such as bananas, onions, garlic, and leeks. Beyond feeding good bacteria, studies show that when FOS is combined with probiotics in a synbiotic, it can improve stool frequency, make stools softer, and reduce straining during bowel movements. Another study reported that synbiotics helped reduce the length of time stool spends in the colon (colonic transit time) while also improving consistency and increasing how often people went to the toilet.

Also, one probiotic strain that has been studied on its own for constipation is Bifidobacterium lactis HN019, which has been shown to shorten gut transit time and improve stool frequency.

Everyday Tips for Relief

Simple, consistent habits can make a big difference:

1. Eat more fibre – aim for 25–30 grams a day from fruit, vegetables, beans, nuts, seeds, and whole grains.

2. Drink plenty of water – hydration keeps stool soft.

3. Keep active – even a short walk can stimulate digestion.

4. Manage stress – yoga, meditation or deep breathing can help balance the gut-brain connection.

5. Consider a synbiotic – certain strains, and combinations with prebiotics like FOS, may help improve bowel regularity.

6. Try kiwi and prunes – studies show that kiwi fruit can improve stool frequency and consistency, while prunes provide fibre and natural sorbitol, which softens stools and promotes bowel movements.

Occasional constipation is normal. But if it lasts longer than three weeks, is severe, or comes with other symptoms such as blood in your stool, unexplained weight loss, or ongoing abdominal pain, it’s best to see your GP.

Conclusion

Everyone’s gut has its ups and downs. Constipation is simply one way it tells you it needs a bit more support. Whether that’s through extra fibre, staying hydrated, or trying a synbiotic, there are plenty of ways to give your gut a gentle nudge in the right direction.

References

Araújo, M. M., & Botelho, P. B. (2022). Probiotics, prebiotics, and synbiotics in chronic constipation: Outstanding aspects to be considered for the current evidence. Frontiers in Nutrition, 9, 935830. https://doi.org/10.3389/fnut.2022.935830

Barberio, B., Judge, C., Savarino, E. V., & Ford, A. C. (2021). Global prevalence of functional constipation according to the Rome criteria: A systematic review and meta-analysis. The Lancet Gastroenterology & Hepatology, 6(8), 638–648. https://doi.org/10.1016/S2468-1253(21)00111-4

Gearry, R., Fukudo, S., Barbara, G., Kuhn-Sherlock, B., Ansell, J., Blatchford, P., Eady, S., Wallace, A., Butts, C., Cremon, C., Barbaro, M. R., Pagano, I., Okawa, Y., Muratubaki, T., Okamoto, T., Fuda, M., Endo, Y., Kano, M., Kanazawa, M., … Drummond, L. (2022). Consumption of 2 green kiwifruits daily improves constipation and abdominal comfort—results of an international multicenter randomized controlled trial. American Journal of Gastroenterology, 118(6), 1058–1068. https://doi.org/10.14309/ajg.0000000000002124

Lever, E., Cole, J., Scott, S. M., Emery, P. W., & Whelan, K. (2014). Systematic review: The effect of prunes on gastrointestinal function. Alimentary Pharmacology & Therapeutics, 40(7), 750–758. https://doi.org/10.1111/apt.12913

Waller, P. A., Gopal, P. K., Leyer, G. J., Ouwehand, A. C., Reifer, C., Stewart, M. E., & Miller, L. E. (2011). Dose-response effect of Bifidobacterium lactis HN019 on whole gut transit time and functional gastrointestinal symptoms in adults. Scandinavian Journal of Gastroenterology, 46(9), 1057–1064. https://doi.org/10.3109/00365521.2011.584895

Yu, T., Zheng, Y.-P., Tan, J.-C., Xiong, W.-J., Wang, Y., & Lin, L. (2017). Effects of prebiotics and synbiotics on functional constipation. The American Journal of the Medical Sciences, 353(3), 282–292. https://doi.org/10.1016/j.amjms.2016.09.014