View photos of the medicinal plant Mentha arvensis (Field mint), profiled in Medicinal Plants of the Western Mountain States.

A passage from  Medicinal Plants of the Western Mountain States:

Field mint is a useful stomachic–carminative, ranking somewhere between Spearmint and Peppermint in strength. All forms: the tea, tincture, spirit, or essential oil are used to reduce the gastrointestinal discomfort of gas pains and bloating. Soothing and anesthetic for irritable bowel suffers, Field mint provides relief, especially during the spastic stages of an episode.