A heavy stomach, bloating, difficult bowel movements... constipation disrupts much more than just digestive comfort; it affects your well-being, your mood, and your entire daily life. Fortunately, simple solutions exist, and they sometimes start with what's in your glass. In this article, let's see what water to drink when constipated and what other measures to take to restore normal and regular bowel movements.
Constipation: why hydration is crucial for digestion
The role of water in intestinal transit
After digestion, waste products arrive in your colon in a semi-liquid form. As they progress, the colonic mucosa reabsorbs some of the water and electrolytes they contain. The contents gradually thicken to form stools, which are normally soft and easy to pass when they reach the rectum.
In cases of water deficit, reabsorption increases: stools become drier, harder, and more difficult to pass.
This is how insufficient fluid intake or significant water loss can contribute to the onset of constipation. This is why adequate hydration is associated with more regular bowel movements.
Magnesium, minerals, and digestion
Drinking enough is a necessary condition, but not always sufficient. The composition of the water you consume can also influence your transit. Some minerals are associated with an osmotic effect according to Bellini et al. (2021). This is particularly true for magnesium: it attracts water into the intestinal lumen, which helps soften stools and facilitate their evacuation. Sulfates are also recognized for their laxative properties at high concentrations, mainly when combined with magnesium.
What water to drink when constipated? A complete guide
Tap water or classic spring water is generally sufficient for hydration, even in cases of constipation. However, some natural mineral waters rich in magnesium and sulfates offer additional benefits due to their mineral profile. Clinical trials, summarized in a review published in Nutrients, suggest that they improve stool frequency and consistency in constipated individuals.
In France, Hépar is the most studied for its effects on functional constipation. This is why it is often cited. Other magnesium-rich mineral waters can also be interesting alternatives, depending on individual needs and digestive tolerance.
| Water | Type | Magnesium (mg/L) | Sulfates (mg/L) | Recommended for | To avoid for |
|---|---|---|---|---|---|
| Hépar | Still | 119 | 1 530 | Effect observed in clinical studies | Infants, sensitivity to strong mineral taste |
| Contrex | Still | 74,5 | 1 121 | Daily use, prevention, low-sodium diet | If a rapid or powerful laxative effect is desired. |
| Rozana | Sparkling | 160 | 230 | Magnesium deficiency, preference for sparkling water | Hypertension, water retention, strict salt-free diets |
| Courmayeur | Still | 68,4 | 1 410 | Difficult transit, high calcium needs, low-sodium diets | Infants, people with very sensitive intestines |
Caution: due to their high mineral content, these waters can cause overly soft stools or diarrhea in non-constipated individuals. Consult your doctor if you suffer from kidney failure.
How much to drink for visible effects
To maintain good hydration, you should drink 1.6 to 2 liters of water per day. This quantity should be adjusted according to your gender, physical activity, and climatic conditions.
If you introduce a natural mineral water rich in magnesium to stimulate your transit, it should replace part of your daily intake, not add to it.
A randomized study conducted on 244 constipated women showed that consuming about 1 liter per day of Hépar was more effective than low-mineral water in reducing hard or lumpy stools.
Note: Increasing water consumption generally does not improve constipation in people who are already adequately hydrated. The benefit only appears when the body is dehydrated.
When to drink water to optimize its effect
Available data do not confirm that one time is better than another. Nevertheless, it may be helpful to drink a glass of water during or just after breakfast.
This period corresponds to when the gastro-colic reflex is naturally more active. This physiological mechanism stimulates colon contractions after meals, with activity generally more pronounced in the morning.
Clinical recommendations also encourage constipated individuals to take advantage of this time to go to the toilet and establish a daily routine (Malone & Thavamani, 2023).
You can then spread your intake throughout the rest of the day.
Alternatives or complements to water for relieving constipation
Useful infusions and hot drinks
Having a hot drink in the morning can, for some people, trigger the urge to have a bowel movement. This effect may also be related to the gastro-colic reflex. However, available data do not show that heat alone accelerates intestinal transit.
Certain herbal teas or infusions like mallow, licorice, ginger, or peppermint are traditionally used to support digestive comfort. However, evidence of their effectiveness in treating constipation remains limited.
Among the most active plants for transit are senna, cascara, frangula, and rhubarb. They are better documented, although the level of evidence varies according to species and available studies (Cirillo & Capasso, 2015).
Juices and drinks to favor
If you prefer cold drinks to relieve constipation symptoms, prune juice is an option to explore. It contains sorbitol, a poorly absorbed sugar alcohol that promotes water retention in the intestine, as well as pectins and polyphenols (Koyama et al., 2022). Apple, pear, and citrus juices with pulp, as well as fruit-based smoothies, are also excellent options.
Cases where water alone is not enough
Lack of dietary fiber
Insufficient fiber intake is one of the most frequent causes of constipation. Be sure to consume 25 to 30 g of fiber per day, as recommended by ANSES, by focusing on foods from different sources: legumes, fruits, vegetables, whole grains.
Low physical activity
Sedentary lifestyle is associated with a risk of constipation, especially in elderly or less mobile individuals. Regular moderate physical activity can help improve your transit, although the effects vary among individuals.
Persistent constipation: when to consult?
Consult a doctor if constipation lasts for several weeks despite hygienic-dietary measures.
Certain signs should also alert you quickly:
- severe abdominal pain or unusual bloating;
- mucus or blood in stools;
- excessive fatigue, lack of appetite, or unexplained weight loss;
- fever or inability to pass stools and gas.
Conclusion
Hydration is a good starting point against constipation, but the choice of water really matters. Natural mineral waters rich in magnesium and sulfates can improve stool frequency and consistency.
Drinking these brands between 0.5 and 1 L per day, spread throughout the day depending on the severity of your condition, is usually enough to observe benefits for transit.
For lasting results, remember to combine them with a fiber-rich diet and regular physical activity. And if constipation persists or becomes painful, don't wait: consult a doctor.
Bibliography
Wang, D. C., Peng, X. F., Chen, W. X., & Yu, M. (2025). The association of moisture intake and constipation among US adults : evidence from NHANES 2005-2010. BMC Public Health, 25(1), 399. https://doi.org/10.1186/s12889-025-21346-x
Dupont, C., & Hébert, G. (2020). Magnesium sulfate-rich natural mineral waters in the treatment of functional constipation : a review. Nutrients, 12(7), 2052. https://doi.org/10.3390/nu12072052
Dupont, C., Campagne, A., & Constant, F. (2014). Efficacy and safety of a magnesium sulfate-rich natural mineral water for patients with functional constipation. Clinical Gastroenterology and Hepatology, 12(8), 1280–1287. https://doi.org/10.1016/j.cgh.2013.12.005
Société Nationale Française de Colo-Proctologie. (2017). Recommandations pour la pratique clinique : prise en charge de la constipation chronique de l’adulte. https://www.snfcp.org/wp-content/uploads/2017/12/livre-RCP-consti2017_long.pdf
Bellini, M., Tonarelli, S., Barracca, F., Rettura, F., Pancetti, A., Ceccarelli, L., Ricchiuti, A., Costa, F., de Bortoli, N., Marchi, S., & Rossi, A. (2021). Chronic constipation : is a nutritional approach reasonable ? Nutrients, 13(10), 3386. https://doi.org/10.3390/nu13103386
Malone, J. C., & Thavamani, A. (2023). Physiology, gastrocolic reflex. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK549888/
Cirillo, C., & Capasso, R. (2015). Constipation and botanical medicines : an overview. Phytotherapy Research, 29(10), 1488–1493. https://doi.org/10.1002/ptr.5410
Koyama, T., Nagata, N., Nishiura, K., Miura, N., Kawai, T., & Yamamoto, H. (2022). Prune juice containing sorbitol, pectin, and polyphenol ameliorates subjective complaints and hard feces while normalizing stool in chronic constipation : a randomized placebo-controlled trial. The American Journal of Gastroenterology, 117(10), 1714–1717. https://doi.org/10.14309/ajg.0000000000001931
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