Peristalsis is an important part of digestion.

Picture of food being squeezed through intestines by peristalsis.

This squeezing motion moves food down your throat, and also through your intestines.

It’s how food gets:

  • down your throat…
  • through your stomach…
  • through your small intestine then…
  • through your large intestine…
  • to it’s final destination the rectum (before exiting out the back door ;).

Peristalsis or “peristaltic action” is what moves food through your entire digestive tract.

When things go wrong with peristalsis, you can end up with bowel cramps, constipation, diarrhea, abdominal pain, etc., (and other things like GERD).

How does peristalsis work?

Your digestive tract is like one long tube from your mouth to your anus (aka, your butt ;). That tube has muscles that squeeze the food along, just like you might squeeze toothepaste from a tube.

Now I know this is an IBS website, and mostly concerned with the last half of your digestive tract, but here’s how the whole thing works:

Peristalsis in action:

  1. A diagram of the human digestive system from throat to rectum.

    This is the trip that the food you swallow takes. And it gets from your throat to the “exit” all by peristalsis.

    You swallow and your mouth pushes food into your esophagus.

  2. Your esophagus has muscles that push the food down into your stomach like a peristaltic wave.
  3. Your stomach squooshes and squeezes (very technical I know) the food around and mixes it with digestive juices etc. It then continues the toothpaste like squeeze, pushing food into…
  4. Your small intestine. Your small intestine does this same rhythic squeezing, continuing the peristaltic action to push the food along. The small intestine absorbs the nutrients from the food as the food moves along. Next stop…
  5. Your large intestine (the colon, or large bowel). Your large intestine absorbs the water from whatever is left from digestion. This allows the body to keep the water, which it needs; and turns the mostly liquid stool or fecal matter into something more solid and easier to excrete out the back. Your large intestine delivers the finished product to…
  6. Your rectum. (this seems awkward to type :). Peristalsis delivers fecal matter (okay let’s just say it, poop), to your rectum where it builds up. When there’s enough to form a “stool” you get the urge to defecate (to poop). Then with one last peristaltic push, the food you ate and digested gets squeezed out of…
  7. Your anus (no planet jokes please :)

For more information about how your digestion works (or doesn’t work) see The Human Digestive System page.

When things go wrong with peristalsis…

Now that you’ve had the tour, I bet you can see where things can go wrong. If something irritates the colon or causes your peristaltic action to move to fast, then the water doesn’t have time to be absorbed. Diarrhea. Often with painful cramps.

If your colon cramps up and prevents the waste from moving through, then it sits too long in the large intestine. The large intestine absorbs too much water from it and it becomes hard. This hardened stool becomes more difficult to pass. These colon cramps or spasms can be very painful.

These are sometimes described as problems with “gut motility.”

What causes problems with peristalsis?

There are a number of different things that can cause problems with the peristalsis process. Caffeinealcohol and cigarette smoking are all suspected of causing problems with peristalsis.

Some people have more nerve endings or pain receptors in their intestines, which can cause spasms in response to food irritants.

Caffeine is a stimulant and bowel irritant which can speed things up to the point of diarrhea. Alcohol can mess things up too (possibly do to the mind gut connection mentioned below).

Some people have a food intolerance that they don’t know about. This can cause abdominal pain, intestinal cramps and (usually) diarrhea.

There is also a connection between the mind and gut which recent studies link to IBS. Also, if you’re prone to IBS, then stress can make IBS symptoms worse.

What helps peristalsis return to normal?

There are some medications your doctor can prescribe that may help with “gut motility” issues. They often work by either speeding peristalsis up or slowing it down.

You can find out if you have a food intolerance using a food elimination diet (the help of a doctor or nutritionist is recommended). If you find that certain foods cause IBS symptoms, then avoid these foods for fewer peristalsis problems and IBS symptoms in general.

Then of course there’s fiber!

Peristalsis and Fiber

Picture of high fiber foods and a sign that says fiber.

Almost nobody gets enough fiber. Fiber helps peristalsis work better.

Almost nobody gets enough fiber. People in the United States (where I live) typically get about 14 to 15 grams of fiber a day. The recommended daily amount is about 30 grams!

Fiber provides something to grab onto when the peristaltic wave is trying to push things through your digestive tract. Fiber also provides structure which helps stool to develop.

It’s better to get fiber from things like vegetables. I’ve always found it difficult to get enough fiber that way (as mentioned elsewhere, I’m a vegetable wimp). My doctor recommended Citrucell which helps a lot, but is expensive.

Psyllium husks don’t work for me at all. They just give me gas, which can lead to IBS cramping! I also find drinking psyllium husks to be pretty nasty. Your experience may be different of course.

One thing about fiber. If you’re going to increase the amount you take in, do it GRADUALLY. A sudden large increase in fiber can cause gas, pain, and trigger IBS symptoms!

In conclusion…

I personally think that if you can remove the irritants (including the stress), and get enough fiber you’d be feeling much better. I know I am.

Let me know what you think in the comments section.