Do Potatoes Cause Constipation? (Or Make it Better?)


In general, potatoes don’t cause constipation. In fact, they often help relieve constipation.

While the cause of constipation is not always clear, I’ll go over the reasoning behind why you probably don’t have to worry about potatoes.

However, there are some cases where potatoes might seem to make constipation worse in the short term, and we’ll go over those as well.

Causes of Constipation

Diet is only one factor that can cause constipation.

Of the most common constipation causes seen below, diet affects 2 of them:

  • Dehydration
  • Low fiber
  • Blockages
  • Diseases (e.g. colon cancer)
  • Nerve damage
  • Other health conditions (e.g. diabetes, pregnancy)
  • Certain medications

There are some serious conditions on that list, so if you or someone you know has chronic constipation, they should see a doctor.

For now, let’s focus on hydration and fiber levels to see why potatoes may be effective for constipation.

Are Potatoes Good or Bad for Constipation?


There are a few reasons why potatoes should be good for constipation in theory:

  • It’s relatively high in fiber, having a mix of soluble and insoluble fiber – Soluble fiber (absorbs water) is known to speed up fecal transit time and encourage bowel movements.
  • Potatoes are easy to digest – While potatoes can cause a bit of gas due to the fiber, potatoes are mainly made of easy to absorb starches and sugars that won’t cause any further digestive problems.

A small potato is about 100 grams, while an average potato is 200-300 grams.

The table below shows the amount of water and fiber in 100 grams of a cooked white or sweet potato.

  White Potato Sweet Potato
Fiber 2.1 g 3.3 g
Water 75.4 g 75.8 g

In a 300 gram potato, there’s 6-10 grams of fiber depending on the type, which is a good amount. 

For reference, the minimum RDA for fiber is 25 grams for adult women, and 38 grams for men. So a single potato can be up to 40% of the RDA of fiber for some people.

In addition, both types of potatoes are about 75% water by weight. Even though it’s usually better to get water by drinking it, getting extra from foods is good as well.

Finally, while there are some better sources of fiber, potatoes do rank fairly high compared to most other fiber sources.


With a good amount of fiber and water, potatoes contain the 2 most important things to start to relieve constipation if dietary issues are the root cause.

Potatoes Could Make Constipation Worse Before It Gets Better

Imagine your bowels like a sewage pipe.

When things get clogged up, you need momentum and pressure to break through and provide relief.

At first, using a plunger on a toilet can push together loose debris and make the blockage even worse, but continued use eventually breaks any large clogs up.

A similar thing can happen in the case of constipation. The fiber in potatoes can absorb water and improve the motility of your gut, but that can bring together other loose material to make constipation worse at first

In most cases however, the potatoes will continue to have a positive effect on movement in your gut and the constipation can be relieved. But there are exceptions to this in bad cases of constipation that may require professional help.

Research on Potatoes and Constipation Relief

There’s actually been a few studies on potatoes and constipation that we can look at.

The first study was done in 120 leukemia patients, who often suffer from constipation. They were given 200 grams of sweet potato per day. Symptoms began to improve within 24 hours, and kept improving during the week-long trial:

On the fifth day, except for “the sensation of anorectal obstruction” and “requirement of manual assistance” in Rome III criteria, other items regarding defecation were significantly improved.

Another study in acute coronary syndrome (ACS) patients with constipation found similar results.


While potatoes aren’t a miracle cure for constipation, there is evidence that they can provide some relief if eaten on a regular basis. More research is needed to identify optimal situations, dosage, timing, and other variables.

Could a Potato Allergy Cause Constipation?

Potato allergies are rare, but even if someone has a potato allergy, it is unlikely to cause constipation.

Instead, there are several more common symptoms associated with potato allergies like:

  • Sneezing
  • Itching
  • Runny noses
  • Hives
  • Breathing troubles
  • Vomiting
  • Diarrhea

Could Eating an Expired Potato Cause Constipation?

Eating a bad potato has the risk of causing food poisoning, similar to most other foods.

However, food poisoning rarely causes constipation as a symptom. The more likely symptoms are:

  • Upset stomach
  • Stomach cramps
  • Nausea
  • Vomiting
  • Diarrhea
  • Fever

Summary: Do Potatoes Cause Constipation?

While eating potatoes may make constipation worse in the short term, they generally have a positive effect on constipation.

This is due to being relatively high in fiber and water.

If you suspect you’re having constipation from something in your diet, it’s likely due to:

  • A different food aside from potatoes
  • Not drinking enough water
  • Not getting enough fiber

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. Chemical engineer turned semi-professional soccer player and freelance nutrition writer. I've been vegan for years and try to make life easier for others by sharing what I've learned.