But simply doing away with offending foods and actions may not alleviate all symptoms of common gastrointestinal issues. In those cases, supplements can stimulate healing from within.

Heartburn, for example, often occurs alongside functional dyspepsia, which includes other symptoms such as bloating and nausea. A German herbal preparation, Iberogast, has been the subject of a dozen human clinical trials on functional dyspepsia and IBS. The formulation includes extracts of peppermint, licorice root, lemon balm, caraway, bitter candy tuft and Matricaria flower (German chamomile). In one study on 120 patients with functional dyspepsia, 43 percent of people who took the botanical blend enjoyed complete relief of symptoms, compared to 3 percent of those who took a placebo.

IBS affects as many as 15 percent of people worldwide. Symptoms include abdominal discomfort, bloating, constipation, diarrhea and gas. One of the better symptom-relieving supplements is peppermint oil. Its primary active ingredient is menthol, which makes up 35 to 50 percent of peppermint oil. A meta-analysis of 121 studies for IBS found peppermint oil was more effective than antispasmodic drugs, antidepressant drugs and fiber. Look for higher levels of menthol in your peppermint supplement.