Antidiarrheals – Herbs for Diarrhea
Diarrhea produces frequent watery stools, often accompanied by cramping pains, urgency, and in serious cases, blood in the stool. Infectious diarrhea is the most prevalent cause of diarrhea worldwide but food sensitivities, inflammation, and medications are also common causes. Oral rehydration solution (ORS) to replace fluid loss is the primary therapy in acute diarrhea but herbs for diarrhea can improve symptoms and increase recovery time. Understanding the differences between the antidiarrheal herbs will help you select the most appropriate ones for your case.
How do herbs for diarrhea work?
Herbs for diarrhea work by several mechanisms. They can treat the underlying cause of diarrhea, reduce water loss and relieve symptoms. The antidiarrheal actions of herbs are divided into different categories:
Mucilage (a type of soluble fiber) absorbs water and forms a semi-solid gel. Mucilaginous herbs act as bulking agents to provide better consistency to the stool to help decrease urgency, give better bowel control, and also reduce water loss. In summary, they help reduce the number of trips to the toilet and accidents en-route.
Astringent herbs are rich in tannins that help suppress diarrhea. Tannins bind to proteins on the bowel walls to alter the permeability and reduce water loss. In addition, astringents make the intestines more resistant to infections by reducing the binding of micro-organism and their enterotoxins to the bowel walls. Furthermore, astringents are used to stop internal bleeding associated with dysentery.
Secretory diarrhea occurs when excess water is pumped into the bowels and/or water absorption is impaired. Water follows the movement of salt (sodium, potassium) in the body. Sodium & potassium are actively pumped from the bowels to increase water absorption thereby hydrating the body. Conversely chlorine ions are secreted into the bowels leading to sodium and thus water loss to hydrate stool but in extreme cases cause diarrhea. The involvement of chlorine transporters (CaCC, CFTR) with diarrhea is supported by research.1 Some antisecretory herbs for diarrhea reduce diarrhea by inhibiting chlorine transporter (e.g. CaCC) and they may also affect the absorption of sodium or potassium.
Caution: Diarrhea helps “flush” out the offending substance or infection that is irritating the bowels. Too much water loss can lead to significant discomfort, dehydration and even death in extreme cases. Therefore suppressing diarrhea with antisecretory herbs or drugs can be useful. However, excess suppression of diarrhea can impede the clearance of infection and may worsen or prolong diarrhea and lead to constipation. Therefore use antisecretory herbs with caution.
Diarrhea is often accompanied with excess bowel motility (peristalsis) resulting in cramping pain and increased urgency to defecate. Antispasmodic and carminative herbs decrease excess motility thus normalizing intestinal movement and reducing cramping pains.
Antimicrobial herbs for diarrhea
Infections are the most common cause of acute diarrhea and some cases of chronic diarrhea as well. Herbs can kill bacteria, parasites, and yeast that commonly cause diarrhea. Based on traditional medicine, several herbs are used to kill diarrhea causing infections.
Commonly used herbs for diarrhea
The following herbs for diarrhea work by various mechanisms. Some of the herbs have significant research to support them while others were selected because of their long history in herbal medicine.
Different species of Psyllium are used as bulking agents. The seeds contain mucilage that absorbs waters and forms a gel. Research shows psyllium reduces diarrhea by increasing the number of normal stools while decreasing watery stools.2,3 This helps reduce water loss and provide better bowel control to reduce “accidents”. Although psyllium lacks significant antimicrobial action, it is useful for infectious diarrhea because it helps controls symptoms without having any suppressive effects on diarrhea like some antisecretory herbs.
Like psyllium, slippery (Ulmus rubra) elm contains some of the highest concentrations of mucilage in herbs and is thus an excellent bulking agent for both diarrhea and constipation. Herbalist use slippery elm as a demulcent for various inflammatory conditions of the digestive tract. Unlike psyllium, slippery elm is also nutritious. Historically, early settlers made it into a gruel and fed to people with sensitive digestive tracts convalescing from serious ailments. Slippery elm lacks clinical trials but remains on of the top demulcents and bulking agents used by herbalists.
Flaxseed (Linum usitatissimum) extracts proved effective against diarrhea. Like psyllium and slippery elm, flaxseeds contains mucilage that absorbs water thus acting as bulking agent. In addition, flaxseed appears to possess antisecretory and antimotility effects that may be mediated via calcium channels.4
In North America, first nation’s people have long used Goldenseal (Hydrastis canadensis) to treat various infections and inflammation of the mucous membranes. In particular, goldenseal is one of the herbs for diarrhea caused by infections. Goldenseal contains berberine, an antimicrobial alkaloid that exhibits activity against diarrhea causing infections including Escherichia coli, Shigella5,6 and giardia.7,8 Moreover, berberine possess antimotility actions and reduces visceral pain by inhibiting mu- and deltoid- opioid receptors.9–11
Different species of oak trees are used in herbal medicine for their astringency. Oak extracts have a strong suppressive action on diarrhea. The oak tannins react with proteins on the surface of mucous membranes to decrease intestinal permeability and reduce bleeding. In particular, gallotannins possess antisecretory activity by inhibiting CaCC.12 Because oak is one of the most astringent herbs it is usually reserved for serious diarrhea.
First Nations people of North America used Cranesbill (Geranium maculatum) to help with wound healing, inflammation of the gastrointestinal tract and diarrhea. The tannin-rich roots give cranesbill its astringency that helps to reduce the permeability of the bowels. Although no research studies exist, studies show that tannins have antisecretory effects this is likely one of the mechanism. Herbalists prefer to use Cranesnill over Oak because for diarrhea because it is less suppresive.
Caution: Astringent herbs for diarrhea should not be used long-term because they can affect nutrient absorption.
Dragon’s blood (Croton lechleri) has long been used by indigenous people in the Amazon for wound healing and diarrhea. This South American herb for diarrhea contains tannins that are highly astringent with antisecretory effects. The active ingredient, crofelemar, inhibits several intestinal chloride channels that cause secretory diarrhea.13 The herbal extract is so effective that it was developed into an approved drug for HIV-drug induced diarrhea. It is widely available as a herbal extract in Latin America but still is relatively difficult to find in North America.
Chamomile has long been used to treat digestive disorders, especially in children because it is very gentle and safe. Research shows chamomile combined with apple pectin (a type of mucilage) improves childhood diarrhea.14,15 Chamomile possesses anti-diarrheal16 effects through its gentle antimotility and antisecretory effects mediate by potassium channels and chlorine transporters (CaCC).17 Furthermore, chamomile has antispasmodic effects to relieve cramping pains often associated with diarrhea17.
Summary of herbs for diarrhea
Herbs for diarrhea work by several different mechanisms. Mucilaginous herbs (e.g. psyllium, slippery elm, flax) absorb water and act as bulking agents to reduce water loss, reduce urgency and improve control of bowel movements. Astringent herbs (e.g. oak, agrimony, cranesbill, dragon’s blood) are rich in tannins that decrease inflammation and possess an antiscecratory effect. Antimicrobial herbs (e.g. goldenseal) kill bacteria and parasites that cause infectious diarrhea. Antispasmodic herbs (e.g. chamomile) have anti-motility and antisecretory effects that help relieve diarrhea. A combination of herbs for diarrhea that works by different mechanisms has the potential to be more effective in treating diarrhea than a single herb.
Author & Photographer: Matt Gowan, BSc, ND
All images are copyright of Matt Gowan ©2017 Reference
Disclaimer: This content is subject to change. The information is intended to inform and educate; it does not replace the medical evaluation, advice, diagnosis or treatment by a healthcare professional. www.nhpassist.com © 2017 NDAssist Inc. and/or its affiliates. All rights reserved.