Upper gastrointestinal (GI) complaints include
Some upper GI complaints represent functional illness Disorders of Gut-Brain Interaction Disorders of gut-brain interaction are characterized by gastrointestinal symptoms of visceral hypersensitivity factors, such as motility disturbance, altered microbiota, mucosal and immune function... read more (ie, no physiologic cause found after extensive evaluation).
Lower GI complaints include
As with upper GI complaints, lower GI complaints result from physiologic illness or represent a functional disorder (ie, no radiologic, biochemical, or pathologic abnormalities are found even after extensive evaluation). The reasons for functional symptoms are not clear. Evidence suggests that patients with functional symptoms may have disturbances of motility, nociception, or both; ie, they perceive as uncomfortable certain sensations (eg, luminal distention, peristalsis) that other people do not find distressing.