The stomach is a muscular, hollow organ in the upper gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach is involved in the gastric phase of digestion, following the cephalic phase in which the sight and smell of food and the act of chewing are stimuli. In the stomach a chemical breakdown of food takes place by means of secreted digestive enzymes and gastric acid.
Peptic ulcer disease is a break in the inner lining of the stomach, the first part of the small intestine, or sometimes the lower esophagus. An ulcer in the stomach is called a gastric ulcer, while one in the first part of the intestines is a duodenal ulcer. The most common symptoms of a duodenal ulcer are waking at night with upper abdominal pain, and upper abdominal pain that improves with eating. With a gastric ulcer, the pain may worsen with eating. The pain is often described as a burning or dull ache. Other symptoms include belching, vomiting, weight loss, or poor appetite. About a third of older people with peptic ulcers have no symptoms. Complications may include bleeding, perforation, and blockage of the stomach. Bleeding occurs in as many as 15% of cases.
The esophagus or oesophagus, colloquially known also as the food pipe, food tube, or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about 25 cm (10 in) long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word oesophagus is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω + ἔφαγον.
Esophageal achalasia, often referred to simply as achalasia, is a failure of smooth muscle fibers to relax, which can cause the lower esophageal sphincter to remain closed. Without a modifier, "achalasia" usually refers to achalasia of the esophagus. Achalasia can happen at various points along the gastrointestinal tract; achalasia of the rectum, for instance, may occur in Hirschsprung's disease. The lower esophageal sphincter is a muscle between the esophagus and stomach that opens when food comes in. It closes to avoid stomach acids from coming back up. A fully understood cause to the disease is unknown, as are factors that increase the risk of its appearance. Suggestions of a genetically transmittable form of achalasia exist, but this is neither fully understood, nor agreed upon.
Heartburn, also known as pyrosis, cardialgia or acid indigestion, is a burning sensation in the central chest or upper central abdomen. Heartburn is usually due to regurgitation of gastric acid into the esophagus. It is the major symptom of gastroesophageal reflux disease (GERD).
Gastroesophageal reflux disease (GERD) or gastro-oesophageal reflux disease (GORD) is a chronic upper gastrointestinal disease in which stomach content persistently and regularly flows up into the esophagus, resulting in symptoms and/or complications. Symptoms include dental corrosion, dysphagia, heartburn, odynophagia, regurgitation, non-cardiac chest pain, extraesophageal symptoms such as chronic cough, hoarseness, reflux-induced laryngitis, or asthma. In the long term, and when not treated, complications such as esophagitis, esophageal stricture, and Barrett's esophagus may arise.
Esophagitis, also spelled oesophagitis, is a disease characterized by inflammation of the esophagus. The esophagus is a tube composed of a mucosal lining, and longitudinal and circular smooth muscle fibers. It connects the pharynx to the stomach; swallowed food and liquids normally pass through it.
A hiatal hernia or hiatus hernia is a type of hernia in which abdominal organs slip through the diaphragm into the middle compartment of the chest. This may result in gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR) with symptoms such as a taste of acid in the back of the mouth or heartburn. Other symptoms may include trouble swallowing and chest pains. Complications may include iron deficiency anemia, volvulus, or bowel obstruction.
Gastric acid or stomach acid is the acidic component – hydrochloric acid of gastric juice, produced by parietal cells in the gastric glands of the stomach lining. With a pH of between one and three, gastric acid plays a key role in the digestion of proteins by activating digestive enzymes, which together break down the long chains of amino acids of proteins. Gastric acid is regulated in feedback systems to increase production when needed, such as after a meal. Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring a regulated pH. These cells also produce mucus – a viscous barrier to prevent gastric acid from damaging the stomach. The pancreas further produces large amounts of bicarbonate and secretes bicarbonate through the pancreatic duct to the duodenum to neutralize gastric acid passing into the digestive tract.
A Nissen fundoplication, or laparoscopic Nissen fundoplication when performed via laparoscopic surgery, is a surgical procedure to treat gastroesophageal reflux disease (GERD) and hiatal hernia. In GERD, it is usually performed when medical therapy has failed; but, with a Type II (paraesophageal) hiatus hernia, it is the first-line procedure. The Nissen fundoplication is total (360°), but partial fundoplications known as Thal, Belsey, Dor, Lind, and Toupet fundoplications are alternative procedures with somewhat different indications and outcomes.
Pyloric stenosis is a narrowing of the opening from the stomach to the first part of the small intestine. Symptoms include projectile vomiting without the presence of bile. This most often occurs after the baby is fed. The typical age that symptoms become obvious is two to twelve weeks old.
Achlorhydria and hypochlorhydria refer to states where the production of hydrochloric acid in gastric secretions of the stomach and other digestive organs is absent or low, respectively. It is associated with various other medical problems.
Gastrointestinal diseases refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum; and the accessory organs of digestion, the liver, gallbladder, and pancreas.
Gastrinomas are neuroendocrine tumors (NETs), usually located in the duodenum or pancreas, that secrete gastrin and cause a clinical syndrome known as Zollinger–Ellison syndrome (ZES). A large number of gastrinomas develop in the pancreas or duodenum, with near-equal frequency, and approximately 10% arise as primary neoplasms in lymph nodes of the pancreaticoduodenal region.
Esophageal dysphagia is a form of dysphagia where the underlying cause arises from the body of the esophagus, lower esophageal sphincter, or cardia of the stomach, usually due to mechanical causes or motility problems.
Gastric outlet obstruction (GOO) is a medical condition where there is an obstruction at the level of the pylorus, which is the outlet of the stomach. Individuals with gastric outlet obstruction will often have recurrent vomiting of food that has accumulated in the stomach, but which cannot pass into the small intestine due to the obstruction. The stomach often dilates to accommodate food intake and secretions. Causes of gastric outlet obstruction include both benign causes, as well as malignant causes, such as gastric cancer.
Laryngopharyngeal reflux (LPR) or laryngopharyngeal reflux disease (LPRD) is the retrograde flow of gastric contents into the larynx, oropharynx and/or the nasopharynx. LPR causes respiratory symptoms such as cough and wheezing and is often associated with head and neck complaints such as dysphonia, globus pharyngis, and dysphagia. LPR may play a role in other diseases, such as sinusitis, otitis media, and rhinitis, and can be a comorbidity of asthma. While LPR is commonly used interchangeably with gastroesophageal reflux disease (GERD), it presents with a different pathophysiology.
In gastroenterology, esophageal pH monitoring is the current gold standard for diagnosis of gastroesophageal reflux disease (GERD). It provides direct physiologic measurement of acid in the esophagus and is the most objective method to document reflux disease, assess the severity of the disease and monitor the response of the disease to medical or surgical treatment. It can also be used in diagnosing laryngopharyngeal reflux.
The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase.
Acid peptic diseases, such as peptic ulcers, Zollinger-Ellison syndrome, and gastroesophageal reflux disease, are caused by distinct but overlapping pathogenic mechanisms involving acid effects on mucosal defense. Acid reflux damages the esophageal mucosa and may also cause laryngeal tissue injury, leading to the development of pulmonary symptoms.
