Possible Causes Of Diarrhea

Written by Liliana Tosic, RHN, RNCP – Nutrition Science Practitioner
Last updated May 19, 2021

Diarrhea can have many underlying causes, such as:

  • Bacterial infection from food poisoning, such as travelers’ diarrhea.
  • Deficiencies of disaccharidase enzymes.
  • Irritation of the colon.
  • Chronic stress and anxiety.

To name a few.

Acute diarrhea, especially in infants and the elderly, can cause dangerous dehydration and salt loss.

Consequently, diarrhea lasting more than a few days should not be ignored. Electrolytes need to be rebalanced, and the root issue found. 

Moreover, alternating constipation and diarrhea could be symptoms of a more serious medical problem, requiring immediate medical attention. More serious causes of diarrhea need to be ruled out first.

Furthermore, diarrhea could also signify that the small intestine lacks the enzymes to break down disaccharide sugars (e.g., lactose, sucrose, maltose, isomaltose). Without enough of these enzymes, undigested and unabsorbed sugars can remain in the gut and osmotically attract large volumes of water, making the stools more liquid. Lactose intolerance is the most common enzyme deficiency of this type.

On a worldwide basis (differing from culture to culture), most adults lack the enzyme lactase needed to break down and absorb lactose, the sugar found in all milk products (except ghee and high-fat cheeses).

For them, total avoidance of dairy such as milk, cream, ice cream, yogurt, cottage cheese, etc., is the only way to ensure relief from diarrhea and other gastro-intestinal disturbances caused by their lactose intolerance.

Stools that are loose and frothy (as opposed to watery) often indicate some form of intestinal malabsorption. These types of stools might contain fats, shreds of mucus, or bits of recognizable, undigested foods.

Whenever absorption is poor, fats tend to pass through the gut, making the stools looser. Mucus is the body’s way of protecting delicate tissues from harm. Its presence in the stools indicates inflammation in the small or large intestine, or both.

Malabsorption occurs in conditions such as lactose intolerance, celiac disease, gluten intolerances, leaky gut syndrome, colitis, and IBS.  All of which involve food allergies or intolerances of one kind or another.

If food sensitivities cause diarrhea, it will be more chronic. Food sensitivities are more common in chronic anxiety sufferers since the digestive system works best in the "rest and digest" environment when the parasympathetic nervous system is engaged.

During stress, the "fight or flight" system – the sympathetic nervous system – is switched "on," compromising digestion, absorption, and elimination. The only measure that can bring lasting relief aside from lowering our overall stress is to track down and eliminate the offending foods.

Additionally, the sensitive body responds to certain types of common foods as if they were poisons. Even a little bit of poison is still poison.

Diarrhea can also deplete beneficial intestinal flora, which can be replenished by a probiotic, such as Lactobacillus Acidophilus. However, probiotics will not work for everyone. Some bacteria in probiotics can make matters worse for some people.

Moreover, histamine intolerance could also be the underlying cause of diarrhea since everyone is somewhat biochemically unique. In this case, specialized probiotics are required that don’t cause the release of more histamine, resulting in more symptoms.

People with histamine intolerance usually exhibit symptoms that overlap with IBS (Irritable Bowel Syndrome), such as diarrhea, constipation, abdominal pain, and burping.

Common histamine intolerance symptoms include diarrhea, constipation, abdominal pain, burping, headaches, nasal congestion, itchy skin/eyes, hives, coughing, etc.

Someone who is histamine intolerant could have all these symptoms or just a few depending on the intolerance severity.

I work with people who suffer from chronic digestive issues. Everyone has different root reasons for their digestive distress symptoms.

Although stress and anxiety often trigger and aggravate digestive issues, the organic cause of the irritation and distress needs to be identified and addressed so that the process of anxiety disorder recovery can continue. 

I’d be happy to help you discover and address your specific reasons if you are having a difficult time with stomach and digestive symptoms, such as the anxiety symptom diarrhea.

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The combination of good self-help information and working with an experienced anxiety disorder therapist, coach, or counselor is the most effective way to address anxiety and its many symptoms. Until the core causes of anxiety are addressed – which we call the underlying factors of anxiety – a struggle with anxiety unwellness can return again and again. Dealing with the underlying factors of anxiety is the best way to address problematic anxiety.

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