Neuroscience

Infectious diseases take time to show clinical signs. The most common is to present a dysfunction of the target organ, that is, if the infection is in the neural system the most common sign is headache, if the infection is pulmonary the most common symptom is cough, if the infection is in gastrointestinal tract, diarrhea. However, there are more general signs such as fever, in appetence and dynamic, which are generalized manifestations that reflect that the organ system is experiencing an infection. There are complementary tests that help in the correct diagnosis of these infections. The diagnosis of gastrointestinal diseases is predominantly related to the patient's history and, to a lesser extent, to the physical examination performed by the physician. Laboratory tests and imaging studies can provide objective evidence for or against a particular disease, among those included in the differential diagnosis and determined by a competent and accurate history and physical examination.

The diagnoses arise from specific symptoms (eg, dysphagia) or gastrointestinal complaints (eg, diarrhea) that accompany extra-intestinal symptoms or physical findings (eg, the arthritis of inflammatory bowel disease or the flush of carcinoid syndrome). However, gastrointestinal symptoms do not originate only from disease or dysfunction of the gastrointestinal tract, but also from the brain-intestinal axis and bloodstream, as well as from dysfunction or pathology of other organs, especially the central nervous system (CNS). For example, a frequent symptom of gastrointestinal disease, nausea and vomiting, can either result from stimulus that affect the CNS or from stimuli originating in the gastrointestinal tract.

https://www.stephypublishers.com/sojnn/pdf/SOJNN.MS.ID.000508.pdf