Can Antibiotics Cause Constipation?

Posted in: Gut Health

IBS Specialists as featured in the Guardian

23 January 2024

By Adam Felman

Reviewed by Victoria Tyler, BSc HONS, BANT


  • Introduction
  • Can antibiotics cause constipation?
  • What is constipation
  • W
  • Symptoms of constipation
  • What causes constipation?
  • Can amoxcillin make you constipated?
  • Antibiotics and yeast overgrowth
  • Natural remedies for constipation
  • Diet for constipation
  • Summary

Constipation is an all-too-familiar health problem. According to the National Health Service (NHS), in any group of seven people at any given time, one of them may be coping with constipation. And it’s not just an inconvenience — constipation can be a source of genuine discomfort that reduces quality of life. 

A range of causes can lead to constipation, from things as simple as routine changes or ignoring your body’s urge to poop to low fluid intake and the side effects of medications, including antibiotics. 

Antibiotics are vital for combatting some infections and keeping people healthy. However, like all medications, antibiotics carry a risk of side effects, one of which is constipation. But how can antibiotics cause constipation? And what can you do to manage constipation when antibiotics are important for a certain treatment?

Can Antibiotics cause constipation?

Yes! If they reduce friendly Gut flora

Numerous studies now indicate that antibiotic treatment leads to a significant loss of diversity and changes in both the quantity and diversity of your friendly gut bacteria. This reduction in friendly gut flora can have a knock on effect of causing irritable bowel syndrome. Antibiotics cause ‘gut dysbiosis’ changing the types and quantities of friendly gut flora within the gut. This lack of diveristy can then cause impaired motility such as constipaton. Source Pubmed

What is constipation?

Constipation means that your bowels are not emptying completely, you’re not passing stools as often as you usually do, or your stools are difficult and painful to pass. Your stool might be dry, lumpy, or hard. There is no “normal” amount of stool to pass every day. Bowel habits look different from person to person. But if you feel like you’re pooping less often than you usually do, you might be constipated.

Constipation happens when stool moves too slowly through your colon. If it stays in the colon for too long, the colon draws fluid from the stool. This can make them dry and tough to pass.

Various factors can bung up your bowels and make stools harder to pass. 

What causes constipation?

  • aging
  • pregnancy
  • frequent travel
  • changing your diet 
  • switching a medication prescription
  • irritable bowel syndrome (IBS), a common, lifelong condition in which the gut does not process food correctly and causes digestive symptoms
  • certain medication side effects
  • a low intake of dietary fibre or fluids
  • infrequent exercise
  • celiac disease, or a severe response to gluten
  • brain and spine disorders, including Parkinson’s disease
  • conditions affecting metabolism, including diabetes
  • conditions that change hormone levels, like hypothyroidism
  • gut inflammation due to conditions like diverticular disease
  • physical blockages of the digestive system

Can Amoxicillin make you constipated?

So you’re taking antibiotics to tackle an infection. Suddenly, your digestive system hits a roadblock. 

The packaging for antibiotics like amoxicillin, penicillin, and doxycycline may not list constipation as a direct side effect. But that’s not the whole story around antibiotics and constipation.

Broad-spectrum antibiotics are a type that attacks a wide range of bacteria, including helpful ones in your gut microbiome — the thriving community of bacteria that promote health reactions throughout the body. Broad-spectrum antibiotics include amoxicillin, some lab-made penicillins, cephalosporins, and doxycycline.

The answer to the question “do antibiotics constipate you?” depends on their effects on your individual microbiome. As healthy bacteria can help to keep your bowel movements ticking over, an unbalanced microbiome can drive constipation, as well as a type of irritable bowel syndrome (IBS) that mainly causes constipation symptoms.

However, it can be difficult to find the underlying cause of constipation. For example, you might have constipation while taking antibiotics for a bacterial infection like Helicobacter pylori (H. pylori), which causes constipation as a symptom.

Remember, it’s always a good idea to consult with a healthcare provider or registered Nutritional Therapist before making any significant changes to your diet.


Antibiotics, yeast infections, and constipation

Yeasts are another group of microorganisms that support gut health – in moderation. However, an overgrowth of yeasts, known as candidiasis or yeast infection, may trigger symptoms similar to IBS if it occurs in the gut. Constipation could be a symptom.

In some cases, an overgrowth of Candida occurs due to an imbalance of healthy gut bacteria caused by antibiotics. The reduction in healthy gut bacteria can lead to constipation.

Natural remedies for constipation

Some natural remedies can help reduce constipation.

Probiotics are fundamental, if you have taken antibiotics you will need to reinoculate the gut microbiome and it is a quick and easy tool. However not all probiotics are made equal and it is vital that you choose a quality brand.

Natural fibre supplements, like psyllium husk, can also make sure people get enough fibre in the diet, bulking out stool and nourishing healthy gut bacteria.

Sometimes, routine is the best natural remedy for constipation. Giving yourself time to have a bowel movement exercising often, and keeping a regular schedule can all support.

It’s best to consult with a healthcare professional before trying home remedies, especially if you’re on medication like antibiotics or living with a chronic condition.

Diet for constipation

Certain foods can support smoother digestion

  • Eat fibre-rich foods: Whole grains, fruits, vegetables, beans, oats, and other high-fibre foods can help to bulk out and soften poops, making them easier to pass. Prunes and figs can be powerful natural laxatives.
  • Avoid junk foods: Low-fibre foods like chips, fast food, fatty meat, and prepared or processed foods can be constipation triggers. Reduce your intake to prevent or manage constipation.

Fluids, fluids, fluids: Liquids including water, clear soups, and naturally sweetened vegetable and fruit juices can help soften stool.


Will antibiotics cause constipation? Constipation and antibiotics have a complex relationship. Antibiotics can protect your health from infection, but it’s important to remember their potential impact on the gut. 

Natural remedies and a gut-friendly diet can be your go-to partners in maintaining a happy, healthy digestive system. If natural remedies and dietary changes don’t relieve your constipation, it may be time to seek a professional opinion. Contact our IBS clinic if you need support.


Booking an appointment

If you need help with digestive symptoms please contact us and we would be pleased to book you in for a consultation at our IBS clinic