Many patients with atopic syndrome complain of symptoms related to irritable bowel syndrome (IBS) as well. Symptoms caused by asthmatic condition or rhinitis are well known to the patients. There are well defined therapeutic strategies on how to handle the cases, well known to the patients. The cause of symptoms under IBS is unclear and many patients undergo many diagnostic procedures including invasive investigations. Quality of life (QOL) is reduced in such patients and they suffer a lot. Psychic disorders like depression and anxiety may occur. At the "end of the Odyssey", food allergies are tested. Patients pay for laboratory tests for specific IgG4 antibodies or alternatively basophile activation tests (BAT) for food incompatibilities offered on online-platforms. In this article, causes of IBS through mast cell activation and not necessarily food allergies are discussed. How does mast cell activation lead to lactose, fructose and histamine intolerance? What are the similarities between Asthma and IBS? Is a similar therapeutic approach feasible?