Does Omeprazole Cause Constipation? Everything You Need To Know

Someone using one finger to flush a toilet.

If you are taking omeprazole and experiencing constipation, you may be wondering if there is a connection between the two.

While constipation is certainly a side effect of omeprazole, it is very uncommon. There is also little scientific evidence that proves the link between constipation and this medication.

However, omeprazole does have a significant impact on the digestive system and gut function, which may be the reason why some people experience constipation.

In this article, we will discuss the link between omeprazole and constipation and provide some advice on how to relieve this side effect.

Understanding Omeprazole

Before we discuss the connection between omeprazole and constipation, you should k now how this medication works and what it is used for.

What is omeprazole?

Omeprazole is a class of medications called proton pump inhibitors (PPIs). Proton pumps are enzymes that can be found in the stomach lining. These enzymes help the body produce acid in order to digest food effectively. PPIs reduce the amount of acid in the stomach.

You can take omeprazole in the form of:

  • Capsules

  • Tablets

  • Liquid

  • Powder for oral suspension

All forms of this medicine are delayed release, meaning that it is not released into the body until it passes through the stomach.

Typically, you will need a prescription to take omeprazole, but it can also be found in the form of a medicine called Prilosec OTC, which can be bought without a prescription. Prilosec OTC is also typically cheaper than prescription omeprazole.

How does omeprazole work?

When there is excess stomach acid in the body, it can lead to health conditions like heartburn, acid reflux, and gastroesophageal reflux disease (GERD). PPIs help treat these problems.

It can also be taken to heal damage to the esophagus and stomach caused by acid.

Omeprazole’s main function is to prevent the tiny proton pumps in the stomach from working properly, which reduces the amount of acid in this muscular organ. This is especially useful if you want to treat GERD symptoms.

This drug may also help to prevent esophageal or stomach cancer and ulcers.

Understanding Omeprazole and Constipation

Now that you know how omeprazole works to reduce stomach acid, let’s look at whether it may cause constipation.

The link between constipation and omeprazole

It’s possible that some people may experience constipation when taking this drug. However, this is not a common occurrence.

Studies have found that omeprazole can cause something called delayed gastric emptying — which is when the rate at which food moves through the digestive system is slowed down.

There is a possibility that this mechanism can result in some constipation.

Most clinical trials that have studied omeprazole have found little supporting evidence that it causes constipation.

Most of the research currently available on constipation is based on the omeprazole capsules. Due to the lack of research, it’s unclear if the tablet form of this medication will cause this side effect.

Other side effects of Omeprazole

Aside from constipation, there are some other potentially unpleasant side effects associated with taking omeprazole.

Nausea and vomiting

It is believed that the delayed gastric emptying associated with omeprazole can make people feel ill or cause them to vomit. One way to avoid this is to take your omeprazole dose with or after meals.


Omeprazole can disrupt the environment of the gastrointestinal tract as a result of reduced acid in the stomach. Changes like these that affect the gut could potentially result in diarrhea.

A lack of stomach acid can cause bacteria to enter the digestive system, disrupting normal digestion and triggering diarrhea.

Stomach pain

There are two main reasons why some people may experience abdominal pain when taking omeprazole:

  • The delayed gastric emptying mechanism we discussed earlier can cause pain and discomfort as food may stay in one place for a longer period of time

  • It can alter the balance of the gut microbiota, which can lead to indigestion and result in pain

Woman clutching her stomach and wincing in pain.


Some individuals may be quite sensitive to the changes omeprazole causes to the body’s chemistry and the way it impacts the digestive system. This may result in headaches.

If you are experiencing diarrhea as a side effect, you could also become dehydrated, which can also cause a headache.

Some people may try to avoid drinking sufficient amounts of water because they are concerned about it causing acid reflux and heartburn. Not drinking enough water can lead to a headache, too.


As mentioned above, omeprazole changes the gut microbiota as well as the digestive system. Imbalances in gut bacteria can increase the production of gas in the body and result in flatulence.

Changes in stomach acid levels can affect the rate at which food is broken down, and it can end up fermenting and creating gas. This can lead to flatulence as well.

Key Point: The Serious Side Effects of Omeprazole

There are some more serious side effects involved with taking this medication than the ones listed above, including:

  • Dark urine, fatigue, and yellow skin which could be signs of liver problems
  • Joint pain
  • A rash, especially on the arms, cheeks, and nose
  • Persistent and severe diarrhea
  • Allergic reactions, which include swollen lips and mouth, trouble breathing, and dizziness or fainting

Side effects of long-term omeprazole use

The Food and Drug Administration (FDA) warns that patients who take omeprazole should not use this medication for more than 14 days at a time.

They also recommend that people not take more than three 14-day courses per year.

This is because the long-term use of omeprazole can lead to adverse effects, including an increased risk of:

  • Bone fractures: Acid in the stomach helps the body absorb the calcium it needs to develop strong and healthy bones. Prolonged proton pump inhibitor use can reduce the absorption of calcium and increase the chance of bone fractures.

  • Gut infections: Stomach acid is responsible for killing bacteria that can cause gut infections. Lack of stomach acid due to omeprazole can result in bacterial infections

  • A vitamin B12 deficiency: The reduction of stomach acid caused by this medication can prevent the body from absorbing vitamin B12 from food

  • Kidney problems: Studies have found that long-term use of proton pump inhibitors may cause kidney injuries

  • Gastric and esophageal cancer: Researchers have found that people who used proton pump inhibitors for more than seven years developed cancer in the esophagus and stomach

  • Liver disease: Proton pump inhibitors change the way the liver works and may cause bacteria to multiply and damage this organ

Other symptoms of using omeprazole for too long may include:

Understanding Constipation

Now that you know it’s unlikely that taking omeprazole is what’s causing your constipation, let’s look at this health problem in more detail.

What is constipation?

Constipation occurs when your bowel movements become less frequent than they typically are. It also involves stools that are difficult to pass.

It’s quite common to develop constipation from time to time, but some people experience chronic constipation.

Constipation is considered chronic if you have fewer than three bowel movements per week.

What causes constipation?

There are certain risk factors that make an individual more prone to constipation. These include:

  • Not including enough fiber in your diet

  • Getting little or no exercise

  • Being dehydrated

  • Being female

  • Being an older adult

  • Certain medications

  • Mental health conditions like depression or eating disorders

How to prevent and ease constipation

There are some ways that you can treat constipation and even prevent it from becoming a problem.

Consider your diet

Including plenty of high-fiber foods in your diet can help you have more regular bowel movements. Some fiber-rich foods include:

  • Whole grains

  • Fruit

  • Vegetables

  • Beans

You may also want to avoid eating processed foods like candy and takeout. Dairy and meat products may also be problematic if you are suffering from constipation.

Stay hydrated

Drinking plenty of fluids can help your digestive system function more effectively. It can help move the food you consume through the body properly.

Water also helps to soften stool, making it easier to pass.

According to the Centers for Disease Control and Prevention (CDC), you should get 125 ounces of water per day from food and drinks if you are male. Females should get 91 ounces of water from food and drinks per day.

A healthy salad and a glass of water.

Prioritize activity

Staying active and getting regular exercise can help prevent constipation because movement lowers the amount of time it takes for food to pass through the digestive system.

As a result, this prevents the body from absorbing too much water from the stool, which makes it dry. Dry and hard stools are more difficult for the body to pass, potentially leading to constipation.

Manage your stress

The hormones that are released in the body as a result of stress and anxiety can change the neurotransmitters in the bowel. This can lead to both constipation and loose stools.

Learning to manage stress is an important part of preventing or easing constipation.

Key Point: Get Help for Anxiety from LifeMD

Through LifeMD, you can get professional anxiety treatment online to help you find peace of mind and comfort.

You will have virtual consultations with a doctor that don’t require any office visits and you can get all the referrals, prescriptions, and medical care you need to manage your anxiety.

Practice good bathroom habits

Practicing good bathroom habits, such as not ignoring the urge to pass stool, can help prevent constipation. It’s also important to ensure that you fully empty your bowels before leaving the toilet.

Consider Taking Omeprazole Alternatives

Remember that everyone’s body reacts to medications differently. What affects you may not affect someone else.

If you are taking omeprazole and you find that your constipation persists or worsens, it might be time to consider alternatives.

There are other medications called H2 blockers that treat conditions like acid reflux and heartburn.

These drugs limit how much hydrochloric acid is produced in the stomach. Some H2 blockers you might want to consider taking as omeprazole alternatives include:

  • Famotidine (Pepcid or Zantac 360)

  • Nizatidine (Axid)

  • Cimetidine (Tagamet)

Another proton pump inhibitor you can try is called Pantoprazole. Nexium (esomeprazole) can also treat erosive esophagitis and GERD symptoms.

When Should I Seek Medical Attention for Constipation?

If your constipation continues for more than three weeks, seeing a healthcare professional for a checkup is important.

You should also see a doctor if:

  • There is blood in your stool

  • You’re experiencing abdominal pain

  • You’re nauseous or vomiting

  • Constipation is a very sudden change for you

Where Can I Learn More About Omeprazole Side Effects?

Through LifeMD, you can consult a doctor or nurse practitioner from the comfort of your home using our telehealth platform.

A licensed medical professional can prescribe omeprazole or alternative medications and will provide advice on their side effects.

Visit our site to make your same-day appointment with LifeMD.

Maria Ablao APRN, FNP-C

Maria, an experienced healthcare professional with over a decade in nursing, advanced to a Family Nurse Practitioner in 2020. Prioritizing prevention and holistic care, Maria emphasizes compassion and adopts a family-centered approach to providing care. Her passion for health and wellness is evident through her commitment to exercise and clean eating, serving as an example to others. Maria advocates for education and improving quality of life in conjunction with treatment.

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This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

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