# Constipation

Category: Conditions

Also known as: slow transit

Constipation is fundamentally a symptom of hypothyroidism and a slowed metabolic rate, which reduces all digestive secretions and the rhythmic muscular contractions of peristalsis. Ray Peat argued that the classical signs of low thyroid function—constipation, dry skin, and…

9 passages · 3 authors · 2008–2026 · Most-cited: [Ray Peat](https://bioenergeticoracle.com/md/voices/ray-peat/index.md)

Canonical page: https://bioenergeticoracle.com/concepts/constipation

## Synthesis

**Constipation** is fundamentally a symptom of *hypothyroidism* and a slowed metabolic rate, which reduces all digestive secretions and the rhythmic muscular contractions of peristalsis. [Source 3, 6, 9] Ray Peat argued that the classical signs of low thyroid function—constipation, dry skin, and falling hair—were common knowledge among doctors fifty years ago, but this clinical perception has been largely abandoned. [Source 9] The resulting **slow transit time** allows for the proliferation of Gram-negative bacteria, increasing the production and absorption of **endotoxin** (lipopolysaccharide), which triggers systemic inflammation, serotonin release, and a further suppression of energy metabolism. [Source 5, 7]

The derangement of intestinal rhythm is not merely a slowing but can involve a *nocturnal reversal of peristalsis*, driven by stress signals from nocturnal hypoglycemia. [Source 1] When blood sugar falls during the night, a chaotic mixture of parasympathetic and sympathetic signals excites the intestine randomly, causing a backward flow that can carry markers from the rectum to the mouth, contributing to bad breath and acid reflux. [Source 1] Peat emphasized that keeping blood sugar stable, particularly by consuming carbohydrates like orange juice before bed, is the first line of defense against this stress-induced reversal. [Source 1] More broadly, physical inactivity is a major contributor to sluggish digestion, as reflexes between the legs and the intestine mean that a daily habit of walking for an hour or so can significantly improve motility and the sense of well-being. [Source 4]

Mechanistically, Peat identified several factors that inhibit peristalsis. A waterlogged, inflamed state of the intestinal tissues prevents the muscles from contracting effectively, an inflammation driven by the conversion of dietary polyunsaturated fats into prostaglandins. [Source 9] Stress increases both adrenaline and the intestine's natural endogenous opiates (endorphins), which act like morphine to halt intestinal action; Peat noted that anti-opiate drugs have been proposed to cure chronic spontaneous constipation for this reason. [Source 9] To counteract these forces, he recommended using **sugar and salt** to lower adrenaline, and sometimes a small amount of thyroid supplement to restore energy production. [Source 9] Aspirin and antihistamines like Benadryl were also cited as simple remedies to lower the inflammatory mediators that cause waterlogging and histamine release. [Source 9]

The strategic use of indigestible fiber is a central intervention. Peat contrasted the average American transit time of 72–76 hours with the 12-hour transit seen in populations eating a diet high in fibrous foods like potatoes, a difference he linked to the huge disparity in bowel cancer incidence. [Source 1, 4] However, he warned that not all fibers are beneficial; some, like lignin, are themselves estrogenic, while others can be fermented by bacteria into toxins. [Source 2] The anti-estrogenic effect of a well-chosen fiber is the result of *accelerated transit*, which speeds the elimination of estrogen excreted in the bile and prevents its reabsorption. [Source 2, 6] This is the basis for the well-known raw carrot salad, which uses a fibrous, indigestible material to stimulate peristalsis, bind endotoxin, and lower the estrogen burden that blocks thyroid function. [Source 6, 7] Georgi Dinkov has extended this framework by highlighting the role of **vitamin B1 (thiamine)** as a key determinant of gut motility, explaining that its bioenergetic role in oxidative metabolism raises CO₂ levels, which has anti-inflammatory and anti-serotonin effects that support proper peristalsis. [Source 7]

When fiber and dietary adjustments are insufficient, Peat acknowledged the historical and physiological basis for using laxatives like aged **cascara sagrada** to prevent the systemic poisoning that arises from a stagnant, inflamed bowel. [Source 5, 6] He challenged the medical campaign against laxatives, arguing that the brown pigmented colon blamed on their use is actually caused by the chronic irritation of constipation itself, and that proper laxative use reduces this irritation. [Source 6] Danny Roddy has noted that while cascara can be a reliable intervention, some individuals find it too aggressive, and that directly addressing thyroid function with a supplement like T3 can sometimes resolve lifelong constipation entirely, making other interventions unnecessary. [Source 8]

## People also ask

### How does hypothyroidism cause constipation?

Peat argued that a low metabolic rate from hypothyroidism reduces all digestive secretions and the rhythmic muscular contractions of peristalsis, directly slowing intestinal transit.

### Why is a raw carrot recommended for constipation?

The raw carrot salad uses indigestible fiber to stimulate peristalsis, bind endotoxin, and accelerate the elimination of estrogen, which otherwise blocks thyroid function and slows transit.

### How does blood sugar at night affect bowel movements?

Peat explained that nocturnal hypoglycemia triggers a stress-driven reversal of peristalsis, and that consuming carbohydrates like orange juice before bed helps stabilize blood sugar to prevent this chaotic backward flow.

## Related concepts

- [Cascara Sagrada](https://bioenergeticoracle.com/md/concepts/cascara-sagrada/index.md)
- [Anxiety](https://bioenergeticoracle.com/md/concepts/anxiety/index.md)
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## Cited passages

Passage numbers match the `[Source N]` markers in the synthesis above.

### Source 1 — One Radio Network: Ray Peat with Patrick Timpone — May 17, 2021

Ray Peat · Passage · May 17, 2021

> **Ray Peat:** I think the first thing is to make sure your intestine is moving along rhythmically. The average American takes about 76 hours for food to move from the mouth to the excretion. And in Africa, in some areas, they've timed it. on an average of 12 hours of very vigorous intestine action when you're active and eating fibrous food. And so just increasing the amount of safe fiber in your food can stimulate the intestine and keep peristalsis going in the right direction. When you're very hypothyroid and when your blood sugar falls during the night, that creates stress signals, a mixture of parasympathetic and sympathetic signals to the intestine, causing the peristalsis rhythm to get deranged, and instead of moving from your mouth through your stomach to the intestine, it goes the other way, and you get a flow backwards. Many years ago, a gastroenterologist experimented on his medical students by inserting a marker into their rectums and then the next morning taking a swab of their saliva. And they found that the students who normally woke up with bad breath and a bad-tasting mouth they found the markers had migrated backwards into their mouth. So it was the habitual intestinal rhythm of a fair percentage of even a very healthy population like medical students. There was a nocturnal reversal of peristalsis.

### Source 2 — Natural Estrogens

Ray Peat · Article · 2008 · https://raypeat.com/articles/articles/natural-estrogens.shtml

> Undigestible fiber, if it isn't broken down by bowel bacteria, increases fecal bulk, and tends to speed the transit of material through the intestine, just as laxatives do. But some of these “fiber” materials, e.g., lignin, are themselves estrogenic, and other fibers, by promoting bacterial growth, can promote the conversion of harmless substances into toxins and carcinogens. When there is a clear “antiestrogen” effect from dietary fiber, it seems to be the result of accelerated transit through the intestine, speeding elimination and preventing reabsorption of the estrogen which has been excreted in the bile. Laxatives have this same effect on the excretion of estradiol. Some of the isoflavones, lignins, and other phytoestrogens are said to prevent bowel cancer, but some of them, e.g., lignin, appear to sometimes increase its likelihood.
>
> The phytoestrogens appear to pose a risk to organs besides the breast and uterus, for example the liver, colon, and pancreas, which isn't surprising, since estrogen is known to be carcinogenic for every tissue. And carcinogenesis, like precancerous changes, mutations, and reduced repair of DNA, is probably just an incidental process in the more general toxic effect of acceleration of aging.
>
> [references]

### Source 3 — Herb Doctors - Endocrincology Part 3

Ray Peat · Interview · May 19, 2017 · http://www.l-i-g-h-t.com/files/herb-doctor-endocrinology-part-3.mp4

> **Ray Peat:** Your digestion slows down when your metabolic rate slows down from hypothyroidism, and so your stomach becomes sluggish, doesn't secrete much and doesn't move fast enough. People might have transit time, they might eat a carrot today, and it might not come out for four or five days. That's what happens with hypothyroidism, and speeding up your digestion and secretions, it should be so active, streaming fluid from your stomach and pancreas and liver should wash your whole small intestine clean so that no bacteria can thrive in it.
>
> **Derek:** And Dr. Peat, real quick, I don't wanna hold you up too long. Is there a, a good quality nutrition-based textbook that you find favorable, that kind of gets into good mechanisms with nutrition and hormones and their relation?
>
> **Ray Peat:** Not that I know of.
>
> **Derek:** (laughs) That's what's tricky. I mean, I know there's some great online databases for some good research that's put out there, but I just didn't know if you had a recommendation there. I really appreciate your time.
>
> **Ray Peat:** Years ago, I've seen some really good monographs on particular topics, like how the intestine works, how the digestive glands work, and so on, but I don't know of one that has put everything together.

### Source 4 — Jodellefit: How to Fix Your Digestion & Poop

Ray Peat · Interview · Sep 10, 2019

> **Jodelle Fitzwater:** Welcome to the Get Fit with Jodelle podcast. I am happy to have Dr. Ray Peat with me here today. Dr. Peat is my go-to source for all things nutrition and health. He has a PhD in biology and has taught at many renowned schools regarding nutrition and women's health. You can learn more about him by visiting raypeat.com. Dr. Peat, I am honored to have you back. I wanted to pick your brain about digestion today. From what I understand, digestion is one of the top five reasons people come to see their doctor. Why do you think there is so much digestive distress in our modern society, and was it this bad 40 or 50 years ago?
>
> **Ray Peat:** One general problem is physical inactivity. People who live in apartments have to take their dogs out for a walk every day because the digestive system tends to slow down when you aren't walking. There are reflexes between the legs and the intestine. In general, physical inactivity affects the whole process of appetite, digestion, and elimination. The change from a crude diet to a very refined diet was also a factor. Around the beginning of the 20th century, health organizations emphasized using whole grains rather than refined flour because of the bulk-forming effect of the bran. Studies comparing Africans and Americans found that because there was a lot of potato and fibrous foods in the African diet, their transit time was about 12 hours. The average American at the time had a transit time of 72 hours. That is a tremendous difference. The rising incidence of bowel cancer in America has been huge, whereas there is almost no colorectal cancer in the undeveloped parts of Africa where they still eat a fibrous diet.

### Source 5 — One Radio Network: Ray Peat with Patrick Timpone — April 18, 2022

Ray Peat · Interview · Apr 18, 2022

> **Ray Peat:** Yeah, and laxatives use is historical and turns out to be very well-based because of the endotoxin thing. When you are... When you've eaten something that you can't digest or you get constipated, an inflammation begins inside your intestine, producing, among other things, lactic acid, histamine, serotonin, and those make your blood vessels that should be a barrier against toxins in your intestine. lets them absorb the endotoxin and that lowers your whole systemic body energy and that can lead to That's from pneumonia in a weak person.
>
> **Patrick Timpone:** Wow. So that's the whole theory behind, or not theory, but the meme behind this whole idea of the immune system and that being in the gut that we've talked about, people have talked about for the last 25 years, right? That's what's going on and why lots of bowel movements is a good thing. Moving things out. About 150 years ago,
>
> **Ray Peat:** a pathologist said, and the coroners recognized bowel inflammation as a major cause of death.
>
> **Patrick Timpone:** Wow. And the bowel gets inflamed because these endotoxins are, when we don't have a sufficient bowel movement in getting things out, it just creates a problem down there, an inflammation, and then it... It causes all kinds of issues.

### Source 6 — One Radio Network: Ray Peat with Patrick Timpone — February 21, 2022

Ray Peat · Interview · Feb 21, 2022

> **Patrick Timpone:** I see. So you use it as a medicine and not something you take every day.
>
> **Ray Peat:** Yeah, although people have taken it every day for decades.
>
> **Patrick Timpone:** Really?
>
> **Ray Peat:** And the first argument was that there might be something wrong with it because chronic laxative users have brown pigmented colons. But doing the study properly, it turns out that constipation and irritation cause the pigmented colon. And proper use of laxatives would be... reducing the irritation and formation of the brown pigment. But that was just part of basically the pharmaceutical FDA campaign against natural substances.
>
> **Patrick Timpone:** So in your opinion, after all these years, what would be like the number one cause behind constipation, which is kind of like an epidemic in our culture?
>
> **Ray Peat:** Slow digestion makes... Every food's a potential.
>
> **Patrick Timpone:** So it starts in the stomach if you're not really digesting the food, right?
>
> **Ray Peat:** And hypothyroidism is the main cause of sluggish digestion.
>
> **Patrick Timpone:** Low thyroid will cause the acid to get messed up and you don't digest well?

### Source 7 — Vitamin B1 (thiamine) may improve gut motility and relieve constipation/IBS

Georgi Dinkov · Article · May 24, 2026 · https://haidut.me/?p=3048

> Gut motility is perhaps the single most important factor controlling endotoxin absorption from the gut into the bloodstream. Constipation increases gut transit time, allowing Gram-negative bacteria to proliferate and release large quantities of lipopolysaccharide (LPS) . Endotoxin then triggers systemic inflammation, serotonin release (90% of serotonin is in the gut), and a host of chronic diseases. Ray Peat has long recommended raw carrot salad (with coconut oil and vinegar) as a gentle, fiber-based way to bind endotoxin and improve motility. I have written extensively about antibiotics (such as penicillin or doxycycline) for more severe cases. Now, a large genetic study published in Gut has identified that vitamin B1 (thiamine) metabolism is a key determinant of gut motility and IBS risk. While the article focuses on the genetic associations, the real mechanism — which the authors do not discuss — is the bioenergetic role of B1 in supporting oxidative metabolism and raising CO₂ levels.
>
> As the study below demonstrates, researchers analyzed data from more than 268,000 people across six biobanks (European and East Asian) and identified 21 genetic locations associated with stool frequency (SF) — a proxy for gut motility. The top variant affects SLC35F3, a gene that transports vitamin B1 (thiamine) into cells. Another variant affects XPR1, a phosphate exporter that is essential for converting thiamine into its biologically active form, thiamine pyrophosphate (TPP) . Observational dietary data confirmed that higher thiamine intake was associated with higher stool frequency (i.e., less constipation), and the effect depended on which gene variants a person carried.
>
> The study concludes that vitamin B1 metabolism plays a “surprising role” in gut motility and opens possibilities for dietary or drug interventions targeting thiamine pathways. But the mechanism is not surprising at all to anyone familiar with bioenergetics. Vitamin B1 (thiamine) is the essential cofactor for three critical enzymes:
>
> - Pyruvate dehydrogenase (PDH) — the rate-limiting enzyme for carbohydrate oxidation. PDH converts pyruvate to acetyl-CoA, allowing glucose to enter the TCA cycle and be oxidized to CO₂.

### Source 8 — Bioenergetic Helpline #1: Intuitive Eating, Bryan Johnson, B-Vitamins, Weight Gain, Power Elite

Danny Roddy · Interview · Nov 29, 2025 · https://www.youtube.com/watch?v=iLoajmu1PNY

> **Danny Roddy:** um yeah i'm not like a it's not like inconceivable to me somebody would have a bad experience with that like some people find it be too aggressive you know for promoting bowel movements and like that that's one of those things are kind of similar to antibiotics that will like change sometimes change a person's life so i think it's worth trying but if you have some odd reaction to it like i think i think investigating thyroid is like the thing that solves constipation i was talking to a girl in new jersey and she was had like lifelong constipation she started taking i think it was like 10 micrograms of t33 times per day and like it on one of the calls she just like moved past the topic but she was asking me about other stuff and um it was kind of classic because this has happened before but she like it just solved her conservation she never brought it up again So, but yeah, when somebody doesn't do well on some like kind of reliable repeat intervention, like I think it's just good to sideline it and maybe return to it later. I mean, that's like the story of everything with my relationship with what Ray said. Like, I don't think I did well on anything he ever said. And it was always lots of troubleshooting and trying to figure it out and why I did not do well with it because I had lots of confidence in him. And so, but yeah, it was very frustrating.

### Source 9 — [RELEASED 2019] Politics & Science: Digestion

Ray Peat · Interview · Apr 26, 2010

> ## Treating Digestive Stagnation
>
> **John Barkhausen:** Part of the digestive process is peristalsis, where the intestine has a contraction that moves food along.
>
> **Ray Peat:** Yes, and if they are waterlogged, the muscles simply can't contract. It's like if your arm swelled up to be two feet in diameter; you wouldn't be able to bend it.
>
> **John Barkhausen:** Are there situations where peristalsis stops and you can use something to get it contracting again?
>
> **Ray Peat:** Sugar and salt are very effective because they lower adrenaline. If stress has stopped your intestine just because of adrenaline excess, sugar, salt, and maybe a little quick thyroid supplement can get it going again. Hypothyroidism's classical symptoms include chronic constipation. But now that so many people are being drugged, there are a lot of opiates being widely prescribed. Everyone knows morphine and opium can cause terrible constipation. The intestine is normally a very rich source of endorphins—the natural endogenous opiates. Stress increases endorphins, and they act just like exogenous opiates: they tend to stop intestinal action. Several people have proposed using anti-opiates (used for treating heroin overdoses) to cure chronic spontaneous constipation, because stress often increases endorphins to the point of causing morphine-like constipation.

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