Overlap syndrome of functional dyspepsia and irritable bowel syndrome - are both diseases mutually exclusive?

Among functional gastrointestinal (GI) disorders, functional dyspepsia (FD) and irritable bowel syndrome (IBS) are important to public health around the world and are frequently encountered in general practice. Upper GI symptoms such as heartburn, postprandial fullness, early satiety, epigastric pain or burning and lower GI symptoms such as constipation and diarrhea often coexist. Although the prevalence of FD-IBS overlap would be influenced by the selection of the study population, the overlap rate of FD-IBS could be in the range of 11%-27%. Specifically, FD-IBS overlap is associated with more severe symptoms than FD alone or IBS alone. Since clinical overlap, especially FD-IBS overlap, is very common, the 2 syndromes should not be treated in a mutually exclusive fashion.