An Herbal Approach to the IBS Patient

Among the most common gastrointestinal disorders worldwide, Irritable Bowel Syndrome (IBS) is a gastrointestinal disorder that interferes with daily living in up to 20% of the population[i]. Considered a functional intestinal disorder, current pharmacological treatment approaches focus solely on reducing symptom severity, and many IBS patients seek further relief to increase their quality of life and support long-term gastrointestinal healing. Patients are often sent away with the assurance that there is “nothing wrong”, and are left to cope with the realities of sporadic cramping pains, alternating diarrhea & constipation, and common co-morbidities including stress, poor sleep patterns[ii], depressive & anxiety disorders[iii], and low-grade systemic and/or lower intestinal inflammation[iv]. There are no clear diagnostic markers for IBS, and so after other similarly presenting conditions have been ruled out it is given as a diagnosis of exclusion, which is concentrated primarily on the patient’s symptom presentation (see Table 1[v]).

The most common symptoms which establish a diagnosis of IBS are:

• Abdominal pain, common in the lower abdominal quadrants, with defecation or passage of flatus often providing relief.
• Abdominal distension, not necessarily linked with increased intraluminal gas.
• Abnormal colonic motility, either diarrhea, constipation, or alternation between the two.

Table 1: Diagnostic (Rome IV) Criteria for Irritable Bowel Syndrome*

Recurrent abdominal pain, on average, at least 1 day/week in the last 3 months, associated with two or more of the following criteria:

• Related to defecation
• Associated with a change in frequency of stool
• Associated with a change in form (appearance) of stool.
  • Predominant constipation (IBS-C)
  • Predominant diarrhea (IBS-D)
  • Mixed/Alternating bowel habits (IBS-M)

*These criteria fulfilled for the last 3 months with symptom onset at least 6 months before diagnosis.

Herbal Approach to IBS

When approaching any gastrointestinal disorder, the enteric nervous system and its relationship to the central nervous system is a key and often overlooked component of conventional diagnostic and treatment approaches. However, the holistically-minded practitioner understands just how crucial this connection can be when confronted with the nebulous diagnosis of IBS, and understands the value of taking a ‘systems vs. symptoms-based’ approach, especially in those with whom the typical western medical interventions have been insufficient. Interestingly, the Eclectics referred to the constellation of IBS symptoms as “Nervous Dyspepsia”, recognizing how intimately connected digestive complaints are related to mental and emotional health; something more current models of research have only begun to explore within the last decade[i].

Many traditionally used herbal therapies support overlapping systems imbalances, and will be explored here in greater detail.

1) Address Abnormal Colonic Motility

Certain motility and sensory abnormalities found in patients with IBS include exaggerated contractile responses to food, stress, and bile acids, which can all alter colonic or small intestinal motor and secretory responses[ii]. Motility disturbances have been reported to occur from the esophagus to the distal colon, with specific transitory disturbances varying with the IBS symptoms (See Table 2). IBS patients also show abnormalities of the Migrating Motor Complex (MMC)[iii] particularly when exposed to stressful stimuli, with neural influences rather than strict myogenic factors appearing to be responsible (e.g. brain-gut interactions). [iv] It is important to remember that both diarrhea and constipation are merely symptomatic expressions of disease, and though herbs can be used to effectively to manage both, the practitioner must always consider addressing the underlying cause in order for the resolution of the condition to occur.

Table 2: IBS-C vs. IBS-D

Constipation predominant (IBS-C)

• Bloating (generally < after meals & at end of the day)
• Abnormally delayed or infrequent bowel movement
• Hard or lumpy stools, difficult to pass with straining, or sensation of incomplete evacuation.

Diarrhea predominant (IBS-D)

• Increased bowel urgency (generally < in the mornings)
• Abnormally frequent bowel movements (rarely an abnormally high stool volume)
• Loose or watery stools, occasionally with mucus & undigested foods

a) Herbal Management of Constipation (IBS-C)

• Bitters & Hepatic Stimulants (Choleretics & Cholagogues) are important herbal action groups with a long use in digestive disturbance to reduce bloating, abdominal pain/cramping, and constipation. Their ability to work through a combination of bile and peristaltic stimulation creates a reflex activation of the MMC and liver/gallbladder, which helps normalize gastrointestinal motility and improve the overall tone of the colonic musculature. As bile is a natural laxative, poor bile output and liver function might contribute towards IBS-C, and so other hepatoprotective herbs may also play a role. Additionally, poor quality or insufficient bile production could be a significant factor in the overall maintenance of healthy bowel flora, and thus its influence on the epithelial cell inflammation response.[i]

Note: Bitters have with much functional overlap with herbal carminatives & nervine tonic/relaxants, often capable of stimulating the parasympathetic nervous system and thus our “rest & digest” bodily functions.

• Bulking (Osmotic) Laxatives are plants that are rich in mucilage (soluble fiber) which are also referred to as bulking agents or stool softeners as they are able to draw water to themselves in the lumen of the colon creating better form & consistency to bowel movements. Although there has been some caution expressed in the use of fiber in IBS as it may exacerbate certain symptoms (e.g. flatulence) in some patients, fiber supplementation has a long history in the management of functional lower GI disorders, and a systematic review of fiber supplementation in IBS found that there was evidence to support an overall reduction in IBS symptoms, particularly with psyllium-based products. [i] Overall, plant based fiber moderates colonic motility and can help enable a physiological balance of the colonic transit to improve constipation and perhaps also have a regulatory action in cases of diarrhea.[ii]

Note: Stimulant or irritant plant laxatives which contain anthraquinones and their glycosides should be avoided due to potential aggravating effects, however Cascara (Frangula purshiana) & Yellow Dock (Rumex cripsus) may be exceptions to this when used in low doses.

Table 3: Primary Herbs & Actions to Consider for IBS-C*

Herbal Actions	Herbal Examples
Bitters, Hepatics, Stimulants, and Hepatoprotectives	Cynara scolymus (Artichoke) Chelidonium majus (Greater Celandine) Gentiana lutea (Gentian) Artemisia absinthium (Wormwood) Berberis aquifolium (Oregon Grape) Taraxacum off. (Dandelion Root) Citrus aurantium (Bitter Orange) Silybum marianum (Milk Thistle) Arctium lappa (Burdock) Schisandra chinensis (Schisandra)
Bulking laxatives	Ulmus fulva (Slippery Elm) Plantago psyllium (Psyllium) Linum usitatissimum (Flax seed) Aloe barbadensis (Aloe vera gel)

*Consider also Carminatives & Antispasmodics, Nervine Tonics & Relaxants

b) Herbal Management of Diarrhea (IBS-D)

• Astringents & Mucus Membrane Tonics have a role in a wide range of problems in many parts of the body, but are of special importance in conditions of the digestive system. Their effects are largely due to a group of complex polyphenolic chemicals called tannins, which have a binding and/or tightening action upon mucus membranes and any tissue they come into contact with. Their therapeutic benefits include a reduction of inflammation and irritation on the surface of tissues due to gentle numbing effect (note: some reports suggest that patients with IBS-D have increased visceral sensitivity compared with those with IBS-C [i]). The effect of tannins is to produce a protective (though temporary) layer of coagulated protein on along the mucosa of the gut wall, thus numbing the sensory nerve endings and reducing provocative stimuli to additional peristaltic activity. Tannins can also affect bowel flora composition, inhibit the viability of infecting micro-organisms, check fluid hypersecretion, improve gut wall integrity, and help neutralize inflammatory proteins.[ii]

Note: Long-term internal or excessive consumption of tannins can be detrimental to health, as there may be an eventual inhibition of nutrient & protein absorption across the gut wall.

Bulking/Osmotic Laxatives are plants that are rich in mucilage (i.e. soluble fiber/bulking agents) have the ability to bind both water & bile acids with the gut[i]. It has been estimated that nearly one quarter of patients meeting then accepted criteria for IBS‐D have bile acid malabsorption.[ii] Thus, dietary changes (e.g. limiting fat intake) and supporting the binding of bile acids within the digestive tract with bulking/osmotic herbal laxatives can in some cases help reduce the impact of too much bile acid in the colon leading to diarrhea and watery stools. Sugar malabsorption (e.g. lactose, fructose & sorbitol) has also received considerable attention in the development of gas, bloating, and diarrhea, though it’s relationship towards IBS is not yet well defined.[iii]

Table 4: Primary Herbs & Actions to Consider for IBS-D*

Herbal Actions	Herbal Examples
Mucus Membrane Tonics and Astringents	Berberis aquifolium (Oregon Grape) Hydrastis canadensis (Goldenseal) Phellodendron amurense (Amur cork tree) Camellia sinensis (Green Tea Grapeseed extract (Vitis vinifera) Capsella bursa-pastoris (Shepard’s Purse) Filipendula ulmaria (Meadowsweet)
Bulking Laxatives **	Ulmus fulva (Slippery Elm) Plantago psyllium (Psyllium) Linum usitatissimum (Flax seed) Aloe barbadensis (Aloe vera gel)

*Consider also Nervine Tonics & Relaxants
**Use caution in cases of excessive bowel mucus or when/if SIBO is suspected.

2) Address Stress, Anxiety & Depressive Disorders

Traditionally, herbal medicine was used alongside lifestyle changes & stress management to treat digestive disorders, and there is a growing amount of research to support the underlying connection between the brain and the gut, and the potential interplay of emotions and mood disorders affecting the severity of IBS symptoms. To quote from Eclectic Physician John Scudder’s approach to treating Nervous dyspepsia, “some very stubborn cases, where melancholy is a prominent symptom will improve rapidly by a change of air, scenery…a sea-voyage, a mountain journey, or a visit to the country will thus accomplish what drugs fail to do”[i].  The effectiveness of low dose TCA and SSRI antidepressants as well as benzodiazepines is yet another indication that the enteric nervous system is influenced by mood, and that innervation by serotonergic and cholinergic neurons in the gastrointestinal tract are thus involved in both intestinal motility & mood regulation.[ii]

• Nervine Tonics & Relaxants are a group of herbs that help relieve stress through promoting parasympathetic nervous system (“rest & digest”) dominance. They are used primarily to support symptoms related to stress, pain, sleep disturbance, and anxiety, and will strengthen & nourish the nervous system when coping with excessive or prolonged periods of tension and/or exhaustion, in some cases helping to restore central and peripheral tissues directly, and/or modulate the action of various neurotransmitters (e.g. GABA, Serotonin). Many also overlap as antispasmodics/analgesics with mild bitter effects, and they are ideally used long-term (minimum 1-2 months) for best therapeutic effects.

Table 5: Primary Herbs and Actions to Consider for IBS Associated with Stress, Anxiety, and Depressive Disorders*

Herbal Actions	Herbal Examples
Nervine Tonics and Relaxants	Matricaria recutita (Chamomile) [i],[ii] Piper methysticum (Kava Kava) [iii] , [iv] Hypericum perforatum (St. John’s Wort) [v] Scutellaria lateriflora (Skullcap) [vi], [vii] Withania somnifera (Ashwagandha) [viii] Passiflora incarnata (Passionflower) [ix], [x] Bacopa monniera (Brahmi) [xi] Lavendula officinalis (Lavender) Centella asiatica (Gotu kola) [xii] Valeriana officianlis (Valerian) [xiii]

*Consider also Carminatives & Antispasmodics

3) Address Intestinal Pain & Inflammation

Pain is a complex, initially protective and adaptive response manifesting as a sensory, emotional, and cognitive phenomenon that can frequently out-live its usefulness and impede the body’s ability to function. It is universal to the human experience, and though it can vary greatly in subjective intensity and duration it is inextricable from the inflammatory process as all pain will involve an inflammatory component.[i] The psychophysiology of visceral pain as it relates to gastrointestinal motility is especially complex, as behavioral variables such as the way an individual manages stress may be as important for its etiology as a history of inflammation. Visceral sensitivity and the mechanisms of processing painful stimuli by the central (e.g. spinal cord pathways and attentional bias at the cortical level) and peripheral (e.g. low-grade mucosal inflammation) nervous systems both appear to play a role.[ii] Herbs will act by helping to resolve inflammatory mechanisms, pain pathways, while reducing stress and spasm within the GI tract.

• Carminatives & Antispasmodics will have a key therapeutic role as herbs that are often rich in volatile oils, causing a mild reflex stimulation in gastric secretions to improve co-ordination of peristalsis, helping to reduce abdominal gas, pain, and cramping. Through their activity the digestive system is stimulated to work with greater ease by coordinating and regulating gut contractions, soothing and settling the gut wall, and thereby reducing gripping pains by supporting the removal of gas from the digestive tract. It should be noted that carminatives are also often smooth muscle relaxants and are thus useful (and synonymous with) antispasmodics/spasmolytics, acting specifically within the gastrointestinal tract. Due to their rich volatile oil content, many carminatives also will have key secondary physiological effects such as being antimicrobial, anti-inflammatory and nervine tonic/relaxants.
• Analgesics & Anti-inflammatories are herbs which can reduce pain, while aiding in the resolution of low-grade systemic or lower intestinal inflammatory processes. They can help reduce irritation & inflammation along the entire length of the intestinal tract through a range of active constituents which may include salicylates, mucilage, flavonoids, resin, curcumin, and others. IBS patients have a reduced threshold to visceral organ pain and are possibly oversensitive to the sensation of bloating.[i] It is presumed that pain symptoms in patients with IBS are produced by motor hyper-reactivity, but these patients also have altered sensation thresholds for stimuli such as rectal and ileal distension [ii] Interestingly, serotonin antagonists (specifically 5HT3 antagonists) are being investigated as agents to inhibit peripheral hyperalgesia in IBS and Ginger has been shown to exhibit this function.[iii] A partially-blinded, randomized, pilot study involving 207 patients with self-reported IBS found that turmeric extract significantly reduced abdominal pain and discomfort as a primary outcome measure after 8 weeks of treatment.[iv]

Note: The presence of mucus in the stool implies irritation and gastrointestinal inflammation.

Table 6: Primary Herbs & Actions to consider for IBS associated with Pain & Intestinal Inflammation*

Herbal Actions	Herbal Examples
Carminatives and Antispasmodics	Mentha piperita (Peppermint) Matricaria recutita (Chamomile) Zingiber officinalis (Ginger) Viburnum opulus (Cramp bark) Filipendula ulmaria (Meadowsweet) Matricaria recutita (Chamomile) Cinnamomum zeylanicum (Cinnamon) Lavandula officinalis (Lavender) Melissa officinalis (Lemon Balm) Dioscorea villosa (Wild Yam)
Analgesics and Anti-inflammatories	Filipendula ulmaria (Meadowsweet) Tanacetum parthenium (Feverfew) Glycyrrhiza glabra (Licorice) Curcuma longa (Turmeric) . Boswellia serrata (Frankincense) , Zingiber officinalis (Ginger) Salix alba (Willow bark) Commiphora molmol (Myrrh) Corydalis ambigua (Corydalis)

*Consider also Nervine Tonics & Relaxants

Other herbal actions which may potentially play a role in therapeutic protocols are outlined in Table 7 and include:

• Adaptogens
• Antimicrobials
• Connective Tissue Tonics
• Demulcents (Vulneraries)
• Hormonal Modulators
• Immunomodulators (Anti-histamine & Anti-allergic)

Table 7: Other Potential Contributing Factors to IBS

Food intolerance/allergy

• Although some studies suggest that patients with predominant diarrhea only respond to withdrawal of specific foods, others have found that all types of IBS respond to some form of exclusion diet. [i], [ii]. Appears to be a subset of IBS patients (typically with diarrhea) who have a strong history of atopy and immunologically-linked true food allergy.[iii]
• Foods which have been found to cause symptoms include cheese, onions, milk, wheat, chocolate, butter, yoghurt, coffee, eggs, nuts, citrus, tea, rye, potatoes, barley, oats and corn.
• Herbal considerations: Scutellaria baicalensis (Baikal skullcap), Tanacetum parthenium (Feverfew), Albizia lebbeck (Albizia), Curucma longa (Turmeric), Matricaria recutita (Chamomile), Glycyrrhiza glabra (Licorice)

PMS (Premenstrual Syndrome)

• Since IBS presents more commonly in women[i] and generally occurs in the premenstrual phase, [ii] it has this been suggested that female hormones may play a role by antagonizing smooth muscle function.[iii]
• Herbal considerations: Vitex agnus castus (Chaste tree berry), Schisandra chinensis (Schisandra), Peonia lateriflora (Peony)

Post-infectious IBS (PI-IBS)

• A disorder wherein symptoms of IBS begin after an episode of acute gastroenteritis. Studies have reported incidence of PI-IBS to range between 5%-32%. The mechanisms underlying its development are not fully understood, but are believed to include persistent sub-clinical inflammation, changes in intestinal permeability and alteration of gut flora. [i]
• Intestinal infections may create hyperalgesia by sensitizing the nervous system in the bowel to over-react to normal stimuli, or alternatively infection or associated antibiotic use, could disturb the normal bowel flora. [ii]
• Herbal considerations: Hydrastis canadensis (Goldenseal), Camellia sinensis (Green Tea), Rosmarinus officinalis (Rosemary), Vitis viniferis (Grapeseed extract), Curcuma longa (Turmeric), Ulmus fulvus (Slippery Elm)

Conclusion

The use of herbal products should be considered an integral component of the management of IBS symptoms, especially when conventional treatment strategies have proved inadequate. As always, when used alongside appropriate diet and lifestyle practices, herbal medicine continues to prove its value and unique ability to improve our mental, emotional and physical health when provided the opportunity to do so, and seemingly, and perhaps knowingly, precisely where we are need of it the most. The exact nature of the herbal treatment should depend on the factors identified in the individual case, however an effective treatment approach should be selected from the following:

1. Address Abnormal Colonic Motility. Whether the patient is experiencing constipation or diarrhea-predominant IBS will determine whether bitters & hepatic stimulants to improve liver function (in the former), or astringents & mucus membrane tonics (in the latter) are most indicated. Bulking (osmotic) laxatives may potentially play a role in either case as plant-based fiber encourages the growth of beneficial bowel flora, moderates colonic motility, and can help enable a physiological balance of the colonic transit transit time in both constipation and diarrhea.
2. Support Parasympathetic Nervous System Activity. Alongside addressing lifestyle & stress management changes, support the underlying connection between the brain-gut axis (enteric nervous system) and the interplay of emotions and mood disorders affecting the severity of IBS symptoms through the use of Nervine Tonic & Relaxant herbs which are are used to relieve stress, pain, sleep disturbance, and anxiety, and will strengthen & nourish the nervous system when used over time. (Ideally a minimum of 1-2 months for best therapeutic effects).
3. Reduce Pain & Resolve Intestinal Inflammation. Herbs can to support the resolution of inflammation, relieve visceral sensitivity, and reduce smooth muscle spasm within the GI tract. Carminatives & Antispasmodics can improve co-ordination of peristalsis, helping to reduce abdominal gas, pain, and cramping and so soothe & settle the gut wall. Analgesic & Anti-inflammatory herbs may also have a role through modification of the perception of visceral organ pain, while aiding in the resolution of low-grade systemic or lower intestinal inflammatory processes.
4. Consider other Potential Contributing Factors to IBS including food intolerance/allergy (whereby an appropriate exclusion diet should be trialed), PMS (Premenstrual Syndrome) and Post-infectious IBS, each of which may require more specialized herbal protocols.