3 Surprising Causes of Constipation

You might not want to reach for that laxative.

white pills on a sheet of paper with "calcium" written in the middle

Medically reviewed in June 2022

Updated on June 20, 2022

Constipation affects about one in every six adults in the United States. Generally speaking, it occurs when you have fewer than three bowel movements over the course of a week, if your stool is hard, or if it’s difficult to get out.

Since constipation is so common, many of us are familiar with natural remedies to move things along: Eat whole grains, don’t skimp on veggies and fruits (prunes leap to mind), exercise regularly, and drink plenty of water. 

What about the causes of constipation? Not surprisingly, a poor diet that mostly consists of foods like red meat, dairy, and fried foods can bring about the condition because they’re all low in fiber. But some other reasons for why things get jammed up might surprise you.

Vitamins and supplements
Wait, vitamins are supposed to be good for you, right? They are, but that doesn’t mean all their effects are entirely beneficial. Iron and calcium, two commonly recommended supplements (iron for anemia, calcium for bone health) are known to cause constipation.

If you’re iron-deficient, experts recommend that you drink extra water and eat a fiber-rich diet while taking supplements—and not take more than you need. 

For calcium, experiment with different forms to see which is least constipating for you. Calcium carbonate and calcium citrate are two of the most common; calcium carbonate tends to cause more constipation. You can also try taking supplements with meals or trying smaller doses throughout the day.

Depression
When you’re depressed, your bowels can be slow. Some studies have shown that constipated people experience depression at rates three to four times higher than normal. 

But researchers aren’t sure if depression causes constipation, constipation causes depression, or it’s a combination of both. The two could be connected in multiple ways:

  • Poor eating habits and lack of exercise due to depression may lead to constipation.
  • Constipation may be a side effect of certain antidepressants.
  • People may simply perceive constipation—along with other pain or negative feelings—more when they're depressed.

It’s possible for the conditions to be physiologically related, as well, or caused by another health issue, such as hypothyroidism.

Laxatives
When used properly, laxatives can help relieve constipation. But overusing or abusing them can lead to more constipation. While it doesn’t exactly cause the condition, it can result in dependency, meaning you can’t go without them. Once you’re dependent, it’s like getting on a carousel: You take laxatives, you can’t poop, so you take more laxatives. Stimulant laxatives, such as Ex-Lax, are most likely to lead to constipation via laxative dependency.

Bottom line: Don’t overdo these over-the-counter solutions. Use them in conjunction with lifestyle changes such as diet, proper hydration, and exercise. And as with any chronic condition, see your healthcare provider if you can’t find relief.

Article sources open article sources

National Institute of Diabetes and Digestive and Kidney Diseases. Definition & Facts for Constipation. May 2018. Accessed June 14, 2022.
National Institute of Diabetes and Digestive and Kidney Diseases. Eating, Diet, & Nutrition for Constipation. May 2018. Accessed June 14, 2022.
MedlinePlus. Taking iron supplements. July 14, 2021. Accessed June 14, 2022.
Harvard Health Publishing. What you need to know about calcium. October 13, 2020. Accessed June 14, 2022.
Sunyecz JA. The use of calcium and vitamin D in the management of osteoporosis. Therapeutics and Clinical Risk Management. August 2008. 4(4), 827–836.
Wienbeck M, Erckenbrecht J, Strohmeyer G. [Effect of antacids on intestinal motility]. Z Gastroenterol. 1983 Mar;21 Suppl:111-6. German.
Gorard DA, Gomborone JE, et al. Intestinal transit in anxiety and depression. Gut. October 1996. 39(4), 551–555. 
Hosseinzadeh ST, Poorsaadati S, et al. Psychological disorders in patients with chronic constipation. Gastroenterology and Hepatology from Bed to Bench. Summer 2011. 4(3), 159–163.
Medscape. Laxatives, Stool Softeners, and Prokinetic Agents. May 18, 2020. Accessed June 14, 2022.
Müller-Lissner SA, Kamm MA, et al. Myths and misconceptions about chronic constipation. American Journal of Gastroenterology. 2005 Jan;100(1):232-42.
ScienceBasedMedicine.org. Constipation Myths and Facts. October 27, 2011. Accessed June 14, 2022.
NIH Office of Dietary Supplements. Iron: Fact Sheet for Health Professionals. April 5, 2022. Accessed June 14, 2022.
NIH Office of Dietary Supplements. Calcium: Fact Sheet for Health Professionals. June 2, 2022. Accessed June 14, 2022.
Cornell Health. Laxative Use: What to Know. October 2019. Accessed June 14, 2022.

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