Peppermint oil has been used for centuries as a treatment for gastrointestinal ailments including IBS symptoms. A systematic review (Ingrosso et al 2022) has analysed randomised control trials and concluded that peppermint oil was useful in the symptomatic treatment of IBS specifically for its antispasmodic property.
Chumpitazi et al also found It appears that peppermint oil may have several mechanisms of action including: smooth muscle relaxation (via calcium channel blockade or direct enteric nervous system effects); visceral sensitivity modulation (via transient receptor potential cation channels); anti-microbial effects; anti-inflammatory activity; modulation of psychosocial distress. Peppermint oil has been found to affect oesophageal, gastric, small bowel, gall-bladder, and colonic physiology. It has been used to facilitate completion of colonoscopy and endoscopic retrograde cholangiopancreatography. Placebo controlled studies support its use in irritable bowel syndrome, functional dyspepsia, childhood functional abdominal pain, and post-operative nausea. Few adverse effects have been reported in peppermint oil trials.
The peppermint oil must be taken as a capsule of enteric coated to be able to reach the colon. It cannot be broken open for easier ingestion as it will not reach the gut. While enteric-coated peppermint oil capsules are generally considered safe for internal use, it’s recommended to consult with a healthcare professional before using the essential oil internally. There can be drug interactions, allergic reactions, increased risk of reflux and diarrhea.
References:
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 Mar;47(6):738-752. doi: 10.1111/apt.14519. Epub 2018 Jan 26. PMID: 29372567; PMCID: PMC5814329.
Ingrosso MR, Ianiro G, Nee J, Lembo AJ, Moayyedi P, Black CJ, Ford AC. Systematic review and meta-analysis: efficacy of peppermint oil in irritable bowel syndrome. Aliment Pharmacol Ther. 2022 Sep;56(6):932-941. doi: 10.1111/apt.17179. Epub 2022 Aug 9. PMID: 35942669.