Functional abdominal pain disorders (FAPDs) in children and adolescents present a complex clinical challenge within the realm of pediatric medicine, characterized by chronic abdominal pain and multifaceted diagnostic criteria. These disorders encompass a spectrum of conditions such as functional dyspepsia, irritable bowel syndrome, abdominal migraine and FAP-not otherwise specified, each exhibiting distinctive symptom patterns. Diagnosis typically involves a comprehensive evaluation, including the assessment of chronic abdominal pain persisting for at least 2 months, absence of alarm findings, normal physical examination, and negative stool sample for occult blood.
Despite being the most common cause of chronic abdominal pain in this young population, FAPDs often lack clear etiology, contributing to the challenge of management. Family medicine practitioners play a pivotal role in the care continuum, often serving as the frontline providers for children with FAPDs. The management goal revolves around restoring normal function rather than achieving complete pain elimination, highlighting the importance of a comprehensive and individualized approach.
This article investigates the promising intervention of peppermint oil, offering insight into its efficacy, safety and potential impact on enhancing the quality of life for children and adolescents grappling with gastrointestinal disorders.
Mentha piperita, commonly known as peppermint, belongs to the Lamiacea family and is found in temperate regions worldwide. The leaf has been utilized as a treatment for various ailments throughout history including the common cold, inflammation of the mouth and pharynx, liver issues and gastrointestinal symptoms including nausea, vomiting, diarrhea, abdominal pain, flatulence and dyspepsia. Iranian mentha species have been found to possess potent antioxidant and scolicidal properties, indicating their potential for developing anti-parasitic drugs. Additionally, it serves as a flavoring agent and is the most commonly used tea in the world.1
Peppermint encompasses a variety of compounds, among them peppermint essential oil (PEO), steroids, flavonoids, triterpenoids, and phenolic acids. PEO is metabolized in the body through conjugation with glucuronic acid and then excreted in urine or feces. Emerging research underscores the multifaceted benefits of PEO, spanning anti-inflammatory, antibacterial, antiviral, scolicidal, immunomodulatory, antitumor, neuroprotective, anti-fatigue, and antioxidant effects. Key constituents in peppermint oil, obtained via distillation of peppermint plant parts, include menthol, menthone, cineole and other volatile oils.
The bulk of peppermint research has focused on PEO, particularly on enteric-coated peppermint formulations. These formulations are designed to reach the lower GI tract directly, avoiding any potential relaxation effects on the lower esophageal sphincter that could contribute to gastroesophageal reflux.2,3
Peppermint has a long history of safe use in medicinal and food preparations. Peppermint is “generally recognized as safe” by the U.S. Food and Drug Administration and there have been no known documented adverse reactions to peppermint tea. However, large doses of menthol (the active constituent in PEO) can cause heartburn, nausea, vomiting, allergic reactions and has been associated with interstitial nephritis and acute renal failure. Additionally, it is believed to have a choleretic effect and is considered contraindicated in patients with cholelithiasis or cholecystitis. It is advisable to exercise caution with PEO among individuals dealing with GI reflux, hiatal hernia, or kidney stones.3,9,10
Historical data suggests that peppermint may have been used both to increase milk supply and inhibit lactation. Both claims lack validation from clinical trials to date. Studies in cell culture and mice have shown that menthol can suppress milk production. However, in humans, menthol is quickly converted to glucuronide metabolite after oral ingestion and it remains unclear whether this metabolite has any effect on suppressing lactation.9
For nursing mothers using PEO to alleviate pain or heal cracked nipples, it is recommended to wipe it off before breastfeeding. Avoid internal or facial use of PEO in infants and young children due to risk of bronchospasm, tongue spasm, and potential respiratory arrest. That said, the quantity of peppermint in over-the-counter medications, topical products, and herbal teas is generally considered safe for pregnant, breastfeeding women, as well as for young children.3
In a study involving 18 lactating women, each given 100 mg of PEO over three test days, menthol was consistently detected in milk samples with concentrations increasing over time from an average of 2.1 mcg/L at 0 hours to a peak of 8 mcg/L. Small amounts of menthol glucuronide metabolites were also found in the milk samples. During the study, mothers reported that none of their infants refused their milk or breastfed less than usual. However, two mothers observed increased agitation in their infants a few hours after breastfeeding. Additionally, a third mother noted occasional pauses in nursing with the infant appearing puzzled, though nursing resumed afterward.
In my experience in pediatric medicine and midwifery, peppermint is well tolerated by breastfeeding infants when given to mothers. Given its historical use for GI issues, it may even be beneficial for newborns dealing with colic-like symptoms. That said, I would advise caution in infants with reflux-type symptoms and also recommend moms listen to their intuition regarding what is working or not working for their little ones.
Managing gastrointestinal pathology in pediatric medicine poses a significant challenge, marked by the complexity of addressing conditions like irritable bowel syndrome (IBS) and childhood functional abdominal pain. Children afflicted by these ailments often experience disruptions to their daily routines, grappling with symptoms like abdominal pain, diarrhea, and nutritional deficiencies. The role of pediatric specialists is to manage these conditions while ensuring proper growth and development. In conventional medicine, treatment typically involves a combination of pharmaceuticals that may include potent medications such as steroids, anticholinergics, antispasmodics and even anti-depressants. In the realm of Naturopathic and functional medicine, the toolbox for management is broader including lifestyle modifications and botanical medicine carefully tailored to each young patient’s needs and often with less risky side effects.
Peppermint essential oil (PEO), recognized historically for its gastrointestinal benefits, has been observed to influence gastrointestinal physiology through mechanisms including smooth muscle relaxation, modulation of visceral sensitivity, antimicrobial and anti-inflammatory effects, and mitigation of psychosocial distress. Its effects span across multiple gastrointestinal organs and have proven beneficial in assisting procedures such as colonoscopy and endoscopic retrograde cholangiopancreatography. PEO’s efficacy has been demonstrated in conditions like irritable bowel syndrome (IBS), functional dyspepsia, childhood functional abdominal pain, and post-operative nausea, with minimal reported adverse effects.4
The origins of these disorders are believed to stem from various factors, including altered interactions between the gut and brain’s neuro-immune systems, such as abnormal gut motility, low-grade inflammation of the gut mucosa, dysregulation of the enteric nervous system, and an irregular composition of gut microbes. The beneficial impact of PEO is likely linked, at least partially, to its antispasmodic properties, which enhance gastrointestinal motility by improving both contractility and transit time. A dose-dependent effect was identified between total menthol systemic exposure and increased gut contractility in a randomized controlled trial published in 2023.5
In a comprehensive review conducted in 2022, menthol was found to activate the transient receptor potential melastatin 8 (TRPM8) channel, offering potential relief for irritable bowel syndrome (IBS) symptoms by inhibiting nociceptive (pain) TRP channels. Peppermint oil was also noted to regulate IBS by significantly reducing pro-inflammatory mediators from nerve endings while concurrently boosting the levels of anti-inflammatory cytokines. Oral administration also appears to prevent xylene-induced intestinal inflammation in mice and acetic acid-induced colitis in rats. Additionally, PEO’s anti-inflammatory action, primarily through mucus secretion, offers gastroprotective effects by activating K+ -ATP channels, ultimately culminating in an anti-secretory effect.2
A 2014 systematic review and meta-analysis aimed to evaluate the effectiveness and safety of enteric-coated PEO capsules in the clinical treatment of active IBS compared to placebo. Nine studies involving 726 patients were analyzed, and the results showed that PEO was significantly better than placebo in improving overall IBS symptoms (P<0.001) and reducing abdominal pain (P<0.001). Although PEO users experienced more adverse events, they were generally mild and temporary, with heartburn being the most common. The study concludes that PEO is safe and effective short-term treatment for IBS, but further research is needed to assess its long-term efficacy and safety compared to other IBS treatments such as antidepressants and antispasmodic pharmaceuticals.6
Of particular interest, a 2022 randomized control trial reported PEO to elevate the abundance of Collinsella, a bacterium typically found in lower levels among individuals with IBS. Considering the bactericidal properties of PEO, there is speculation that it could offer positive effects on functional disorders by influencing the composition of the gut microbiome. Imbalances in the gut microbiome, known as dysbiosis, are thought to play a role in the development of symptoms associated with functional GI disorders with a higher relative abundance of Bacteroides and lower abundance of Faecalibacterium spp., and Akkermansia spp. To date, research has not validated a significant effect of PEO on these species.7
A systematic review published in 2017 evaluated the effectiveness and safety of herbal treatments for gastrointestinal disorders in children. Among 14 trials involving 1927 participants, several herbal treatments showed promise. Potentilla erecta, carob bean juice, and an herbal compound with Matricaria chamomilla were effective for treating diarrhea. Additionally, various fennel preparations were effective for infantile colic. And, our hero, peppermint essential oil was found to decrease the duration, frequency and severity of pain in children with undifferentiated functional abdominal pain. No serious adverse reactions were reported.8
The research appears to back the use of PEO as an avenue in managing pediatric gastrointestinal complaints, particularly conditions like IBS and childhood functional abdominal pain. Its multifaceted effects, ranging from smooth muscle relaxation to anti-inflammatory properties, make it a versatile treatment option. PEOs efficacy has been demonstrated in various studies, showcasing its potential in alleviating symptoms and improving overall gastrointestinal health. Moreover, its safety profile as evidenced by minimal reported adverse effects, further supports its use in pediatric patients. However, while existing research highlights its short-term benefits, further investigation is warranted to fully understand its long-term efficacy and safety, especially in comparison to conventional pharmaceutical treatments. Nonetheless, the emerging evidence underscores the potential of PEO as a valuable therapeutic agent in pediatric gastroenterology, offering hope for improved management and outcomes in young patients suffering from gastrointestinal disorders.
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2. Zhao H, Ren S, Yang H, et al. Peppermint essential oil: its phytochemistry, biological activity, pharmacological effect and application. Biomed Pharmacother. 2022;154:113559. doi:10.1016/j.biopha.2022.113559
3. Kligler B, Chaudhary S. Peppermint Oil. Am Fam Physician. 2007;75(7):1027-1030.
4. Chumpitazi BP, Kearns GL, Shulman RJ. Review article: the physiological effects and safety of peppermint oil and its efficacy in irritable bowel syndrome and other functional disorders. Aliment Pharmacol Ther. 2018;47(6):738-752. doi:10.1111/apt.14519
5. Shulman RJ, Chumpitazi BP, Abdel-Rahman SM, Garg U, Musaad S, Kearns GL. Randomised trial: Peppermint oil (menthol) pharmacokinetics in children and effects on gut motility in children with functional abdominal pain. Br J Clin Pharmacol. 2022;88(3):1321-1333. doi:10.1111/bcp.15076
6. Khanna R, MacDonald JK, Levesque BG. Peppermint Oil for the Treatment of Irritable Bowel Syndrome: A Systematic Review and Meta-analysis. J Clin Gastroenterol. 2014;48(6):505. doi:10.1097/MCG.0b013e3182a88357
7. Thapa S, Luna RA, Chumpitazi BP, et al. Peppermint oil effects on the gut microbiome in children with functional abdominal pain. Clin Transl Sci. 2022;15(4):1036-1049. doi:10.1111/cts.13224
8. Anheyer D, Frawley J, Koch AK, et al. Herbal Medicines for Gastrointestinal Disorders in Children and Adolescents: A Systematic Review. Pediatrics. 2017;139(6):e20170062. doi:10.1542/peds.2017-0062
9. Peppermint. In: Drugs and Lactation Database (LactMed®). National Institute of Child Health and Human Development; 2006. Accessed March 25, 2024. http://www.ncbi.nlm.nih.gov/books/NBK501851/
10. Charrois TL, Hrudey J, Gardiner P, Vohra S. Peppermint Oil. Pediatr Rev. 2006;27(7):e49-e51. doi:10.1542/pir.27-7-e49
