Overview

• Recent summaries highlight peppermint, chamomile, ajwain, fennel and cumin as traditional remedies with some modern support for easing common digestive symptoms.
• Clinical trials show peppermint oil capsules can relieve IBS symptoms, though menthol may worsen acid reflux by relaxing the lower oesophageal sphincter; peppermint tea is a gentler option.
• Chamomile remains largely supported by traditional use and animal data, with one small study showing faster relief of infant colic, though some people may be allergic.
• Fennel’s anethole relaxes gut muscles in lab studies and a small IBS trial reported less cramp‑like pain; its seeds add insoluble fibre, with the NHS recommending about 30g of fibre daily.
• Cumin appears to boost digestive enzymes and bile and shortened gut transit in animals, with a small IBS trial of 57 people reporting symptom relief within two weeks, while ajwain shows similar mechanisms in animals but limited human data and high‑dose pregnancy risks.