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Acute infectious gastroenteritis is the strongest known risk factor for the development of irritable bowel syndrome (IBS), one of the most common functional gastrointestinal disorders. The knowledge about the incidence and prevalence of post-infectious IBS (PI-IBS) in the general population is still limited. Risk factors have been identified in the development of PI-IBS. These include the virulence of the pathogen, younger age, female sex, the long duration of the initial illness and the presence of psychological disturbances. Histopathologic data demonstrate a low-grade mucosal inflammation in a subset of patients with IBS. Furthermore, a change in intestinal microflora could also be involved although confirmatory studies are required. The use of probiotics or non absorbable antibiotics during the acute infective episode could play a preventive role. Nonetheless, the discovery that an infective episode may trigger the development of IBS has not substantially changed the clinical management of this subset of patients compared to the classical (non infective) form of IBS. Future studies aimed at identifying specific therapies are waited.

Gastroesophageal reflux disease (GERD) can be described as a clinical picture resulting from the reflux of stomach contents into the esophagus. The actual prevalence of GERD remains unestablished, although this disorder is generally common in old patients, male sex and in subsets of patients with pulmonary manifestations such as asthma. From a pathophysiological stand-point, GERD is thought to have a multifactorial etiology which involves genetics, anatomical, functional, environmental, hormonal and pharmacological factors. GERD has different clinical presentations which may be divided in three main classes: typical symptoms (heartburn and regurgitation); atypical or extraesophageal symptoms (angina-like chest pain, asthma, chronic cough and laryngitis); and complications (ulcers, strictures and Barrett's esophagus). In GERD diagnosis a key role is played by: accurate symptom evaluation, response to proton pump inhibitors and, finally, at least one in a life-time endoscopy. Moreover, barium swallow X-ray, 24-h esophageal pH monitoring and gastro-esophageal manometry can be useful to support diagnosis in some unusual cases or in cases partially or unresponsive to standard pharmacologic treatment.

Multiple Endocrine Neoplasia type 1 (MEN 1) syndrome comprises tumors or hyperplasia of different glands, including parathyroid, pituitary, adrenal cortex and the gastroenteropancreatic system. The vast majority of MEN 1 are found in familial clusters, although a few cases are sporadic. Hypercalcemia and/or nephrocalcinosis are the first and most common clinical manifestation in familial MEN 1 syndrome, followed by islet cell tumors (especially those secreting gastrin or insulin) and pituitary dysfunction due to either functioning or non-functioning microadenomas. Genetic studies indicate that familial MEN 1 syndrome is inherited through a dominant gene with incomplete penetrance and variable expression. The diagnosis of MEN 1 syndrome is mainly based on the careful assessment of the clinical history, symptoms physical evaluation along with the assay of serum electrolytes (i.e., calcium, phosphorus, etc.) and hormonal substances (i.e., gastrin, insulin, pancreatic polypeptide, prolactin, adrenocorticotropic hormone, etc.). In addition, several provocative tests have been used to identify endocrine tumors (particularly those of the gastroenteropancreatic system) and imaging techniques play a crucial role for the diagnostic approach in MEN 1 syndrome. Even though in the long term, the prognosis of MEN 1 syndrome is unfavourable. Recently, however, many therapeutic strategies, including both surgical and pharmacological options, have been developed to reduce the size of the neoplasm and control symptoms associated with hormone oversecretion.

The innervation of the alimentary tract (or enteric nervous system, ENS) represents the third division of the autonomic nervous system and it appears to be unique for its intrinsic ability to mediate reflex activity even when disconnected from the central nervous system. Enteric nerve cells can be classified in subclasses according to combined classic morphological criteria (Dogiel type I, II and III) and electrophysiological properties (type S and AH). A further major feature of the ENS lies in the variety of chemical messengers expressed in its neuronal elements. These substances can act either as neurotransmitters or neuromodulators. A common finding of enteric neurons is to synthetize and store several chemical messengers, a phenomenon known as neurochemical coding. As a consequence, neurotransmission involves the release and action of more than one messenger, an event referred to as plurichemical transmission. Recently, the use of combination of methods (such as immunohistochemical, pharmacological and electrophysiological techniques) has led to the identification of specific functionally distinct categories of enteric neurons. Thus, inhibitory and excitatory motor neurons, interneurons, vasomotor and sensory neurons are now recognized to constitute the complex network of the ENS. These neuronal elements are synaptically connected to form microcircuits which play a pivotal role to control digestive functions, including motility, blood flow, secretion and absorbtion.

Traditionally, the stomach is regarded as two functional unit regions: 1) a proximal portion mainly involved in receptive relaxation and emptying of liquids; and 2) a distal portion that grinds, mixes and empties solids. Manometric and radioisotopic studies have been employed to construct such a physiological model. More recently, ad hoc designed studies have led to the identification of other factors that contribute to the regulation of gastric emptying. Antral, intestinal and pyloric motility, fundic tone and antropyloroduodenal coordination appear to be all involved in the regulation of gastric emptying. Nowadays, no single technique can simultaneously measure those parameters. Gastroduodenal manometry can be regarded as the most advanced technique, in studying gastrointestinal motility. Nevertheless, fundic tone, which is an important determinant of gastric emptying, cannot be concurrently recorded.

The influence of Thyropramide, a recently developed spasmolytic on the gastric emptying times of a solid meal was assessed in 10 healthy subjects aged 23-54. Thyropramide (300 mg per diem for 3 days per os) does not significantly modify gastric emptying time compared to the placebo though a slight average increase in T 1/2 was noted. No side effects were noted during the study. Thyropramide therefore appears to have a spasmolytic effect on the large intestine without in any way influence the stomach either proximally or distally.