This post was written by Apexa Patel, PharmD Candidate, Parkview Pharmacy.
Constipation is something many people experience at some point, but not everyone realizes that vitamins and other medications may be the cause.
You may start a new supplement or prescription medication and suddenly notice you’re feeling bloated, uncomfortable or not having regular bowel movements like normal. The good news is that this is a common issue, and in many cases, there are simple ways to help manage or prevent it.
What is constipation?
Constipation can look different for different people. For some, it means having fewer bowel movements than usual. Others may notice hard stools, straining or feeling that they still need to go even after using the bathroom.
Occasional constipation can happen because of dehydration, diet changes or stress. Certain vitamins and medications may also slow digestion.
Vitamins and supplements that may cause constipation
Iron supplements: Iron supplements are one of the most common causes of constipation. While iron is important for treating or preventing anemia, it can sometimes make stools harder to pass. Some people may also notice stomach discomfort or darker stools while taking iron supplements. If this happens, rather than stopping iron on your own, it is recommended that you speak with your healthcare provider or pharmacist. They may be able to recommend a different formulation or suggest ways to help reduce these side effects.
Calcium supplements: Calcium supplements, especially calcium carbonate, the main ingredient in some antacids such as Tums®, can also contribute to constipation. This can become more noticeable if you are not drinking enough water or getting enough fiber in your diet.
Multivitamins: Some multivitamins contain both iron and calcium, which may increase the chance of constipation, especially if taken daily.
Medications that commonly cause constipation
Many medications can slow the movement of the intestines, making bowel movements less frequent or more difficult. Some common examples include, but are not limited to:
-
Opioid medications used to treat pain, such as hydrocodone, oxycodone and tramadol.
-
Certain antidepressants, such as amitriptyline, nortriptyline and paroxetine.
-
Some blood pressure medications, including verapamil, clonidine and certain diuretics also known as water pills.
-
Antacids containing calcium or aluminum e.g. Tums®, Mylanta®, Maalox®.
-
Allergy medications such as antihistamines, including diphenhydramine and chlorpheniramine.
-
Some antibiotics, especially those that are broad-spectrum, may cause constipation, diarrhea or both because of their unintended effects on healthy gut bacteria. Examples include Augmentin®, azithromycin and clindamycin.
-
Bladder medications with anticholinergic effects, such as oxybutynin and tolterodine.
Many of these medications fall under a broader category called anticholinergic medications, which can slow digestion and have a “drying” effect on the body, sometimes making constipation more noticeable. Not everyone experiences constipation from these medications, but it’s helpful to be aware of the possibility.
What can help?
Fortunately, small daily habits can often make a big difference.
Drink more water. Staying hydrated helps keep stools soft and easier to pass. Many people simply do not drink enough fluid throughout the day.
Add fiber slowly. Foods like fruits, vegetables, oats, beans and whole grains can help support regular bowel movements. Adding fiber gradually is important because too much too quickly may cause bloating or other unwanted side effects.
Stay active. Even light physical activity, such as walking, can help keep the digestive system moving.
Talk to your pharmacist or healthcare provider. Sometimes adjusting the timing, dose or type of supplement may help reduce constipation. A pharmacist can also review your medications to see if any may be contributing to the problem.
Don’t ignore ongoing symptoms. While occasional constipation is common, persistent symptoms should not be ignored. It is recommended to speak with your healthcare provider if constipation becomes severe, painful, sudden, lasts longer than two to three weeks without improvement or does not improve after about one week of lifestyle changes or over-the-counter treatments. Seek medical attention sooner if constipation is accompanied by symptoms such as severe abdominal pain, vomiting, blood in the stool or unexplained weight loss.
The bottom line
Constipation can be uncomfortable, but it is often manageable once the cause is identified. Vitamins, supplements and medications can all play a role, but small lifestyle changes and medication adjustments may help improve symptoms and support better digestive health.
Many of these tips are helpful for adults; however, constipation in children should be addressed more cautiously. If a child is experiencing ongoing constipation, abdominal pain or changes in bowel habits, it is recommended to speak with a healthcare provider or pharmacist for guidance before trying supplements or medications on your own.
If you are experiencing ongoing constipation, talk with your pharmacist or healthcare provider before stopping any prescribed medication. They can help you find the safest and most effective solution customized to your individual needs.
References:
-
Black CJ, Ford AC. Chronic idiopathic constipation in adults: epidemiology, pathophysiology, diagnosis and clinical management. Medical Gastroenterology. Med J Aust. 2023;218(2):86-92. doi:10.5694/mja2.51828.
-
Shin A, Camilleri M. Diagnostic assessment of constipation and irritable bowel syndrome with constipation. Gastroenterol Clin North Am. 2021;50(3):513-532. doi:10.1016/j.gtc.2021.04.002.
-
https://www.mayoclinic.org/diseases-conditions/constipation/symptoms-causes/syc-20354253
