People ask me about herbal remedies for constipation. Honestly, I am not even sure where one would find some of this stuff, and why you would seek it out when the mainstays such as psyllium husk (which is a natural fiber) work so well. But it was fun to look into, so now I have answers when people ask me in the office. As always, this post is for informational purposes and is not medical advice. If you’re thinking about starting any of these, please check with your health care provider first.
Slippery elm is classically used as a demulcent / mucilaginous herb. Its mucilage may coat mucous membranes in the GI tract, providing lubrication and possibly easing stool passage. (PMC)
Some sources cite that it may stimulate mucus production or moderate nerve activity in the GI tract, though high-quality clinical studies are lacking. (Healthline)
In an in-vitro gut microbiota study, U. rubra (slippery elm) altered microbial composition and increased representation of butyrate-producing bacteria, which might favor colonic health. (PMC)
The evidence is mostly traditional / anecdotal; I did not find robust randomized trials specifically demonstrating its efficacy for constipation.
A review of alternative GI treatments mentions slippery elm being used in mixtures (with lactulose, oat bran, etc.) for minor GI ailments, but not as a monotherapy under rigorous trial settings. (PMC)
Because slippery elm is mucilaginous and viscous, it may interfere with absorption of concurrent oral medications (if taken too close in time). (Healthline)
There is limited evidence on safety, so caution is prudent, especially in vulnerable populations (do NOT use in pregnancy, children, etc.).
Also, slippery elm is considered endangered by certain plant conservation groups, so ethical sourcing is a concern. (PMC)
Bottom Line: I do NOT recommend it.
Cascara’s laxative effect is attributed to anthraquinone glycosides (cascarosides) which act as stimulant laxatives: they irritate the colon, increase peristalsis, and inhibit reabsorption of water/electrolytes in the colon, thereby promoting stool passage. (NCBI)
It is considered a “purgative / stimulant herb” rather than a gentle fiber-like laxative. (Memorial Sloan Kettering Cancer Center)
The European Medicines Agency (EMA) herbal monograph (for Rhamni purshianae cortex) concludes that cascara bark preparations may be used for the short-term treatment of occasional constipation under certain conditions. (European Medicines Agency (EMA))
In the U.S., cascara was removed from the FDA’s over-the-counter laxative monograph in 2002 because of safety and evidentiary concerns; it is now marketed as a dietary supplement, which has different regulatory oversight. (Verywell Health)
WebMD notes that people “use cascara sagrada for constipation … but there is no good scientific evidence to support” its long-term use. (WebMD)
Cascara is generally safe for short-term use, but there are documented risks of liver injury (hepatotoxicity) when used at high doses or prolonged durations. (NCBI)
Other side effects: abdominal cramping, electrolyte imbalance, diarrhea, dehydration, melanosis coli (dark pigmentation of colonic mucosa) with chronic use. (Memorial Sloan Kettering Cancer Center)
Because of the risk of liver toxicity, cascara is generally recommended only for brief durations, often no more than a week, and under medical supervision. (NCBI)
Cascara may also interact with other drugs, and contamination with mycotoxins (due to fungal growth on bark) has been flagged as a potential safety issue in some analyses. (Consensus)
Bottom Line: I do NOT recommend it.
Flaxseed is rich in dietary fiber (both soluble and insoluble), and its mucilaginous (gel-forming) components can help soften stool, increase fecal bulk, and accelerate transit. (MDPI)
It also contains lignans and other bioactive compounds; there is interest in its effects on gut microbiota, which might help modify gut function over time. (Dove Medical Press)
A randomized controlled trial in adults with chronic functional constipation found that flaxseed flour (vs. lactulose) improved defecation frequency, Wexner constipation scores, and quality of life. (PubMed)
Another trial (flaxseed vs psyllium / placebo) evaluated 10 g flaxseed and found improvements in constipation symptoms, though direct superiority vs psyllium was not firmly established. (ScienceDirect)
Animal studies suggest both flaxseed oil and mucilage exert laxative effects via gut stimulation. (ScienceDirect)
Reviews and meta-analyses indicate that flaxseed is a promising, gentle option in constipation management. (MDPI)
Flaxseed is generally considered safe when used in dietary amounts. (Dove Medical Press)
Excessive intake without adequate water may worsen constipation or lead to bowel obstruction, especially in individuals with strictures or motility disorders.
Because flaxseed contains phytoestrogens (lignans), caution is sometimes advised in hormonal conditions, though for constipation use (moderate amounts) this is less a concern.
Also, as with any fiber supplement, start gently, increase fluid intake, and monitor for gas, bloating, or changes in bowel habit.
Bottom Line: I DO recommend flaxseed fiber, and in fact add a teaspoon to my overnight oats.
Bitter orange (often standardized to synephrine) is best known for its stimulant / thermogenic properties, but its role in constipation is less well documented.
Some herbal sources list bitter orange as a mild stimulant, but I did not find strong clinical evidence supporting its use as a laxative.
No well-designed clinical trials evaluating bitter orange specifically for constipation relief.
Because of its known stimulant / adrenergic effects, its use in GI motility must be viewed cautiously, and most evidence centers around weight loss, circulation, or metabolism, not bowel function.
Bitter orange (and its components like synephrine) can affect cardiovascular system (blood pressure, heart rate) and may interact with stimulants or cardiovascular drugs.
Using bitter orange as a laxative without solid evidence is risky given its systemic pharmacological activity.
Bottom Line: I do NOT recommend it.
In traditional / folk medicine, elderberry and elder flower have been used for various purposes including colds, inflammation, and (less strongly) constipation. (GovInfo)
The notion is that elder preparations may have mild diuretic or purgative activity in folk use, but evidence is scant. (GovInfo)
Modern pharmacological / clinical evidence supporting elder (for constipation) is very limited. The NIH / National Center for Complementary and Integrative Health fact sheet notes that “no reliable information is available on the effectiveness of elderberry and elder flower” for uses including constipation beyond traditional use. (GovInfo)
The monograph states that although elder has been used traditionally for constipation, scientifically rigorous trials are lacking. (GovInfo)
Unripe or uncooked elderberries contain cyanogenic glycosides, which can cause nausea, vomiting, or diarrhea if consumed improperly. (GovInfo)
Also, elderflower may have mild diuretic effects; combining with other diuretics or in conditions of fluid imbalance should be done cautiously. (GovInfo)
As always, safety in pregnancy, lactation, or in children is not well established.
Bottom Line: I do NOT recommend it.
So, you know that I am Chinese and I have a healthy respect for traditional medicine and herbal medicine. There’s a whole chapter in my book about it. I am not saying these things don’t work. People and cultures who have used these remedies for centuries will continue to do so, regardless of what I say. All I’m saying is, there’s no Western medical literature to support using some of these herbs, and as I am a Western trained doctor, I have to tell you that.
Hydration and diet first: Increasing dietary fiber, water intake, and promoting physical activity are foundational in constipation management. Herbal remedies are adjunctive.
Start gently: For fiber-type herbs (like flaxseed), introduce slowly to allow adaptation; for stimulant herbs (cascara), use lowest effective dose and only for short duration.
Time medications appropriately: Mucilaginous herbs (slippery elm, flax) may reduce absorption of co-administered medications; space timing and check with your health care provider if you’re on medications that require blood testing for levels (for example, thyroid medications, antiepileptics, blood thinners)
Monitor for side effects: Especially abdominal cramping, diarrhea, electrolyte disturbances, signs of liver stress (for cascara) which can include jaundice (turning yellow).
Avoid combining multiple strong stimulant herbs without supervision.
Consult health professionals: Particularly in special populations (pregnancy, children, liver disease, kidney disease, concurrent medications).
Source quality matters: Herbal preparations vary; contaminants, adulteration, mislabeling, or poor processing are risks.
Until next time, that’s just the way the anus wrinkles.
