FODMAP stands for “fermentable oligosaccharides disaccharides monosaccharides and polyols" and include fructans (wheat, pastries, pasta), galactans (chickpeas, lentils, beans, soy), lactose (all dairy products), fructose (honey, apples, pears), and polyols (sugar alcohols such as sorbitol and stone fruits such as as avocado). Foods range in their amount of FODMAPs, some having very low amounts that are unlikely to cause stomach issues, to foods that have very high amounts which are most likely to cause problems.
FODMAP containing foods may only cause side effects when eaten in large amounts (i.e. the American diet) so just because your favorite food is on the high FODMAP list does not necessarily mean it needs to be completely eliminated from your diet. Figure out if you have sensitivity to FODMAPs by cutting out FODMAP containing foods for a few weeks and then slowly re-introducing them back into your diet one at a time, and/or pay attention to how you feel after eating FODMAP rich foods.
Below is a list of FODMAP containing foods - from low amounts of FODMAPs to high amounts.