Low Stomach Acid & Irritable Bowel Syndrome: What’s The Connection?

Mark Volmer
Apr 21, 2017 · 7 min read
irritable bowel and low stomach acid
irritable bowel and low stomach acid

Hypochlorhydria or low stomach acid could be at the root of your digestive issues.

What is hypochlorhydria?

Hypochlorhydria or low stomach acid is a condition where an insufficient amount of acid is being produced by the stomach before or during meals. (1) Achlorhydria is indicative of having an absence of stomach acid.

In general, one’s stomach acid should have a pH of less than 3.0. This is considered the normal range. Values above a ph of 3.0 are considered to be low in stomach acid production. Values above a pH of 7.0 are considered to be achlorhydric. (2)

What are the consequences of having low stomach acid?

Symptoms of low stomach acid span a full spectrum of digestive tract related disorders. There are two specific ways in which poor digestion can affect the health of your digestive tract: (3)

  1. A decreased ability to absorb nutrients
  • If the body struggles to absorb specific nutrients, there is going to be a deficiency of that nutrient.
  1. Allowing unprocessed food particles to be accessed by bacteria in the digestive tract
  • When bacteria are able to ferment a greater amount of food, they can create;
  • gas
  • bloating
  • nausea
  • urgent bowel movements
  • burping
  • stomach pain
  • If this condition is present for a long period of time, or, if it is severe, there can by physical changes to the bacteria in the digestive tract.
  • This may include an overgrowth of bad bacteria in the small intestine (SIBO). (4)
  • Additionally, changes in the time it takes for the stool to move through the digestive tract may occur. This will result in either constipation or diarrhea.
  • SIBO and variations in stool transit time are often strongly correlated with irritable bowel syndrome. (5)

To summarize, a condition as seemingly harmless as low stomach acid can result in large changes to the digestive tract. At times, these changes can be so dramatic that they cause irritable bowel syndrome.

How does our body control stomach acid production?

Now that you know how important stomach acid production is to digestive health, it’s important to understand how our body regulates acid production.

The cephalic phase of digestion occurs before any food enters our stomach. The sight, smell, or thought of food is what stimulates this. The hungrier your are, the greater the response will be.

At this time, our body releases a substance called acetylcholine from the vagus nerve. The vagus nerve is the nerve that controls our stomach. Once acetylcholine is released, it stimulates specific stomach cells called parietal cells. The parietal cells activate the body’s proton pump which stimulates stomach acid production.

Have you ever taken a proton pump inhibitor?
They’re often prescribed for heartburn or GERD (gastroesophageal reflux disease). Proton pump inhibitors stop the parietal cells from releasing stomach acid. This decreases the levels of acid found in the stomach. (6)

Proton pump inhibitors have been linked to impaired absorption of calcium, iron, folic acid, vitamin B6, and vitamin B12. (7,8) Adequate levels of stomach acid also play a key role in eliminating ingested bacteria/parasites. Low stomach acid has been shown to increase the risk for conditions like SIBO and clostridium difficile infections. (9,10)

Stomach acid production and aging

As we age, our stomach naturally decreases the amount of acid it produces. One study found that hypochlorhydria occurred in only 10% of elderly Americans, yet in over 60% of elderly Japanese. The study concluded that the food consumed is likely to have an effect on one’s stomach acid production. (11)

While the amount of stomach acid may not decline substantially as we age, the time required for the stomach to keep up acid production does change. Another study showed that the time required for the stomach to re-acidify after eating was 42 minutes in younger subjects. In the elderly, it took nearly 89 minutes for the stomach to reacidify. (12, 13)

The study concluded that low stomach acid may contribute the following symptoms often found in the elderly:

  • poor protein digestion
  • reduced micronutrient absorption
  • an increased risk of bacteria infections (SIBO, clostridium difficile)
  • gas and bloating

Low stomach acid and GERD

The most common treatment for acid reflux or heartburn are medications that reduce the production of stomach acid. These are often called proton pumps inhibitors or hydrogen blockers. Yet, there’s almost no evidence to suggest that those suffering from heartburn have an excess of stomach acid.

A study done at USC measured the stomach acid of 1,582 patients suffering from heartburn. Researchers found that these subjects had a fasting stomach acid pH of 1.7. Normal subjects had a fasting stomach acid pH of 1.5. Not much a difference in stomach acid levels. Additionally, 11% of the participants had low stomach acid. (14)

In the same study, patients with low stomach acid reported significantly more acid reflux symptoms when lying down than those with normal or high levels. The current thought is that stomach acid levels may be less important. More important is the stomach’s ability to clear acid that has moved up the stomach. (15)

How to increase stomach acid

The following are commonly recommended to increase stomach acid production:

Digestive bitters

Digestive bitters consist of bitter-tasting plants or plant extracts that are often distilled in an alcohol solution. Digestive bitters are common in many herbal medical traditions as a way to assist digestion. (16)

Bitters often consist of: gentian, artichoke leaf, endive, dandelion leaf, wild lettuce or chicory. These can be used individually or in a commercially prepared combination.

Please note that at the time of this writing, there is little information available on the specific dose or ideal preparations.


In some individuals, coffee can increase heartburn symptoms; even though its pH is only between 5 and 6. Thus making it not very acidic.

Research done in vivo has shown a number of compounds found in coffee that help to stimulate stomach acid production. (17)

Do keep in mind that using coffee as a means to increase stomach acid production has not been studied. Therefore, working with a knowledgeable practitioner will be of greatest benefit.

Betaine HCL

Betaine hydrochloride (HCl) is a chemical substance used increase stomach acid. It is by far the most popular and direct means to lower the pH in the stomach (remember, a lower pH is a more acidic environment).

Betaine HCl can be purchased over-the-counter throughout health food stores in Canada. Typically, one pill contains 65mg of betaine HCl.

The effective dosage of betaine is unique to you. To find the proper dose, we follow an empirical model used to determine your effective dose.

In the one study involving betaine HCl, researchers were examining if betaine could re-acidify the stomach after one had taken a proton pump inhibitor. Subjects in the study were given acid-blocking drugs until their stomach pH reach 4.0. They were then given 1500mg of betaine HCl. Britain was shown to lower the subject’s stomach acid to a pH of 0.6 thirty minutes after supplementation. Betaine kept the subjects stomach acid below of pH of 3.0 for more than seventy minutes. (18)

How do you know you have low stomach acid?

Complaints such as gas, bloating, muscle cramps, epigastric heaviness and easy satiety can relate to a hypochlorhydric state, although the condition can also be asymptomatic.

Clinical presentation can vary widely, and hypochlorhydria should always be considered in patients with deficient states of depleted micro- and macromolecules, low vitality, and changes in gastrointestinal function. If you’ve been diagnosed with irritable bowel syndrome, checking stomach acid levels should be one of the initial investigations done.

Signs may include deficiencies of vitamins and minerals, muscle cramps and twitches, acne, food allergies, dilated capillaries on cheeks and nose, brittle and peeling nails, and halitosis.

The Heidelberg test:
The Heidelberg test involves a capsule containing a pH-sensitive radio-transmitting device has been in use since the 1960s. A small pH sensor is swallowed, and gastric acid fluctuation is evaluated before and after ingestion of a baking soda solution. (19) As this test is expensive to run, it is rarely used in clinical settings.

The betaine challenge test: (20)
This protocol involves taking increasing doses of betaine HCl at mealtimes until a noticeable discomfort is reported.

For example, let’s imagine that healthy stomach acid levels are equal to the number 50. If you go above that number, you’ll likely experience heartburn. So, for those with low stomach acid, if they supplement betaine up to a level of 50, there will be no symptoms. If your stomach acid levels are normal and you supplement betaine, you’ll likely experience heartburn. Other commons signs of discomfort include:

  • feelings of unease
  • digestive discomfort
  • tingling
  • heartburn
  • diarrhea
  • neck or back ache
  • headache

If you suspect you have low stomach acid, follow the below steps to determine if betaine is right for you:
* If you do experience any negative or uncomfortable symptoms, you can neutralize the acid by taking 1 tsp of baking soda dissolved in water or milk.
* Do not take more than 3000mg of betaine HCl

  1. Begin by taking 1 capsule containing 350–750mg of betaine HCl with a meal containing a palm-sized (4oz) serving of protein. Please ensure this is part of a sufficient sized meal. ~500 calories are best.
  2. If there is no discomfort or burning sensation experienced, increase your dose to 2 pills of betaine HCl during the next day’s meal. Ensure meal size is similar for each test.
  3. If there are still no noticeable reactions to the betaine after two days of supplementing, increase the dose to 3 capsules.
  4. Continue to increase the number of capsules every two days (if necessary) until a dose results in tingling, burning, or any other type of discomfort.
  • At this point, decrease your dose by one capsule per meal. This is your effective dose.
  1. Once your dose is established, continue at this dose during meal times.
  • With smaller meals, less betaine will be needed. You can lower your dose accordingly.


  • Do not take betaine HCl if you have peptic ulcer disease.
  • HCl can irritate sensitive tissue and be corrosive to teeth — therefore
  • NSAIDs and Corticosteroids increase the chances of ulcers in the stomach and, together with Betaine HCL, increase the risk of gastritis.

Ok, now you have the information needed to determine if low stomach acid is contributing to your irritable bowel.

Originally published at Flourish Clinic.

Mark Volmer

Written by

I help those with fatigue naturally reclaim their energy and share their gifts with the world.

Mark Volmer

Written by

I help those with fatigue naturally reclaim their energy and share their gifts with the world.

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