Gastroenterology is defined as the diagnosis and treatment of diseases affecting the entire digestive system including the esophagus, the stomach, the small and large intestines, the liver, the pancreas, and the gall bladder.
Irritable bowel syndrome ("IBS") and dyspepsia are some of the most common functional GI disorders. A functional disorder does not show any evidence of an organic or physical disease, and the cause of a functional GI disorder is not detected in blood tests or X-rays. Such disorders are diagnosed based on symptoms, and lifelong treatments are often required to alleviate these symptoms. The symptoms due to such disorders can cause discomfort, ranging from inconvenience to deep personal distress. For those individuals who experience severe symptoms, the disorders can be debilitating and seriously affect their personal and professional lives.
Other than IBS, conditions such as pancreatic insufficiency, inflammatory bowel disease and cholestatic liver disease fall within the category of GI diseases and disorders. The costs related to the treatment of such diseases represent a tremendous economic and social burden.
Much remains unknown about gastrointestinal diseases and disorders. Consequently, there is a critical need to support more research, which Aptalis has done for the past 25 years through its research efforts designed to benefit scientific knowledge and lead to advanced therapies in the field of gastroenterology.
Muscular tube that transports food by peristalsis from the pharynx to the stomach. Both ends are closed off by sphincters (muscular constrictions), which relax to let food through and close to keep food from backing up.
The liver is the body's largest internal organ, weighing about 1.5 kg or 2.5% of body weight. The liver and biliary system produce bile and transport it to the small intestine, where it breaks up fats and other diet components, and aids the digestion and absorption of nutrients. Approximately 1 L of bile is produced daily and enters the small intestine.
The pancreas is a digestive and endocrine organ located behind the stomach in the upper abdomen. The pancreas secretes digestive juices containing enzymes into the duodenum to help break down food into smaller molecules that can be absorbed. It also secretes insulin into the bloodstream to maintain the appropriate concentration of glucose in the blood.
The stomach is a digestive sac in the left upper abdominal cavity, which expands or contracts depending on the amount of food it contains. It has four regions: the cardia leads down from the esophagus; the fundus curves above it; the body is the largest part; and the antrum narrows to join the duodenum at the pyloric valve. Iron and very fat-soluble substances (e.g., alcohol and some drugs) are absorbed in the stomach. Peristalsis mixes food with enzymes and hydrochloric acid from glands in the lining of the stomach and moves the resulting chyme toward the small intestine. The vagus nerve and sympathetic nervous system control the stomach's secretions and movements.
The small intestine is the longest section of the digestive tract, with an average length of about 6 m. Although only 2.5cm in diameter, its surface area for absorption covers the size of a tennis court. Large quantities of nutrients and water can be absorbed in the small intestine. Daily, it is capable of absorbing: several kilograms of carbohydrate; up to 1 kg of fat; 500 g of proteins; and 20 L of water. The surface cells of the small intestine are highly specialized for digestion and absorption of nutrients. Almost all of the body's nutrient absorption occurs in the small intestine along its three sub divisions: the duodenum, the jejunum and the ileum.
The colon, also known as the large intestine, is the final organ of the digestive process. It is responsible for drying out indigestible food residues by absorbing fluid and producing solid waste (faeces) for elimination. Approximately 1.5 m long, the colon has six distinct regions leading from the join with the small intestine: cæcum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum.