How long should we wait for functional dyspepsia to develop?

Improvement of social hygiene and decreased H. pylori prevalence has resulted in the decrease of gastric organic diseases such as gastric ulcers and/or cancers. However, the number of patients with dyspeptic symptoms does not seem to have decreased, probably due to increased life stress and complicated social structures. Accordingly the attention to functional dyspepsia is rapidly increasing, and such a trend has also accelerated the scientific approach for this condition. It is crucial to provide a strict definition of this condition in order to investigate this disorder with scientific basis. Rome Committee is the most well-known and prestigious research organization; it has published a definition for FGIDs, which are used worldwide. The definition of FD by this committee has been revised twice, in accordance with advancement of understanding of this condition. After the first definition of this condition in 1991 (1), the first revision was made and published as Rome II criteria in 1999 (2), and Rome III criteria was published in 2006 as the second revision (3). As is well known, in the latest version of Rome definition, the dyspeptic symptoms are limited to the following four independent symptoms: postprandial fullness, early satiety, epigastric pain and epigastric buring. A factor analysis of a variety of dyspeptic symptoms resulted in the selection of these four symptoms, which has successfully made this condition greatly simplified. The former two symptoms were classified as postprandial distress syndrome and the latter as epigastric pain syndrome. The definition also determines the duration of this disease. It is well known that this condition has a chronic nature, and the definition must define “chronic” by an actual length of the time. In the first definition, it was one month, and in the second definition, Rome II criteria, patients need to have the symptoms for at least 12 weeks of the preceding 12 months. In the third definition, it is determined that these symptoms should last for 3 months with symptom onset being at least 6 months before the diagnosis. Like this, the definition regarding the time frame is varied, suggesting the difficulty to define “chronic” by the actual length of the time. On the other hand, it seems as though there is not much evidence to support their validity. On the other hand, the duration must be altered by various situations. The consulting behavior of the patients, culture and temper of the ethnic group may affect it. The interpretation of “chronicity” may be different according to various countries or populations. In this issue of this Journal, Kinoshita and Chiba (4) provided unique evidence for this thesis in an intelligent maner. They surveyed the characteristics of patients with chronic gastritis and compared them with those of functional dyspepsia who met the Rome III criteria. As a result, they found that not only the clinical characteristics, but also the severity of symptoms and quality of life of chronic gastritis were not different from those of FD patients defined by Rome III criteria. Most interestingly, they found that the severity of the symptoms was similar regardless of duration of the symptoms. Their findings provide the scientific basis that the duration of symptoms is not necessarily defined so strictly at least in our patient population. It is obvious that this finding cannot be simply applied to other regions or patient populations. However this kind of study would address the right time frame in the definition of functional dyspepsia, and their study suggests that Rome III criteria needs validation according to different countries, at least regarding the duration of the symptoms.