People generally get stomach cramps or other irritations from eating bananas due to either banana intolerance or banana allergies, according to SteadyHealth.com. Although these conditions yield similar symptoms, they do not necessarily mean the same thing. However, not many people experience cramps from eating bananas from either of these rare conditions.
Dr. Angelica Giron explains that stomach aches after eating bananas may be a sign of food intolerance, a condition not related to an immune system reaction. More people have food intolerance than they do food allergies. However, people who experience allergic reactions to latex may also have a cross-reaction to proteins in bananas, which produces symptoms including gastrointestinal upset, itching, hives and respiratory symptoms. Testing for a banana allergy is done via an oral food challenge, a blood test, or a skin prick test.
Dr. Bhupinder Kaur also notes that a banana food allergy stems from an overreaction of the immune system to the protein chitinase, while banana intolerance involves vaso-active amines that sometimes trigger symptoms that can mimic allergy reactions. Specifically, the vaso-active amine serotonin in bananas sometimes causes cramping, flushing of the skin, headaches and heart palpitations. Both doctors recommend that people who experience these symptoms avoid eating bananas and suggest seeing a physician to get tested.