Acid reflux: the backflow of stomach acid into the esophagus. Acid reflux generally occurs because the lower esophageal sphincter (LES) relaxes and allows harsh stomach juices to flow into the esophagus.

Acid blockers: medicines that slow down the production of acid in the stomach to treat heartburn and acid indigestion. Proton (or acid) pump inhibitors and H2 blockers are the two main types of acid blockers.

Angina (also called angina pectoris): discomfort or pressure, usually in the chest, caused by a temporarily inadequate blood supply to the heart muscle. Discomfort may also be felt in the neck, jaw, or arms.

Antacids: medications commonly used for the treatment of heartburn. Antacids treat heartburn symptoms as they occur and work by neutralizing acid in the stomach for a short period of time.

Appendix: a small, finger-like tube located where the large and small intestine join. It has no known function.

Barium swallow: an X-ray study used to view the mouth, throat, esophagus, and stomach. During the test, you eat and drink foods and liquids mixed with a special substance that will provide an outline of your mouth, throat, esophagus, and stomach.

Barrett's esophagus: a condition marked by an abnormal lining of the esophagus that develops in response to acid injury. This condition increases the risk of cancer of the esophagus.

Bile: a substance that aids in the digestion of fat and eliminates waste products from the blood.

Biliary system: the gall bladder and bile ducts.

Biopsy: the removal of a sample of tissue for study, usually under a microscope.

Cannulas: tubes that hold the laparoscope and instruments, and allow access to the abdominal cavity for performance of laparoscopic surgery.

Carcinoma: malignant (cancerous) growth that tends to invade surrounding tissue and metastasize (travel to and grow in) to other regions of the body. The tumor is firm, irregular, and nodular, with a well-defined border.

Clinical trial: a research program conducted with patients to evaluate a new medical treatment, drug, or device.

Colon: see large intestine

Diaphragm: the muscular wall separating the chest cavity from the abdomen.

Digestive tract: the system that turns the food you eat into the energy your body needs to survive. The digestive system extends from the mouth to the throat, esophagus, stomach, small intestine, large intestine, rectum, and anus. The pancreas, salivary glands, liver, and gallbladder all connect to the digestive tract, producing essential substances for healthy digestion.

Duodenum: the first part of the small intestine that connects to the lower part of the stomach.

Dysphagia: difficulty swallowing.

Endoscope: see laparoscope

Endoscopy: a method of physical examination using a lighted flexible instrument that allows the physician to see the inside of the digestive tract. The endoscope can be passed through the mouth or through the anus, depending on which part of the digestive tract is being examined. This method is referred to by different names, depending on the area of examination, such as: esophagoscopy (esophagus), gastroscopy (stomach), upper endoscopy (small intestine), sigmoidoscopy (lower part of the large intestine), and colonoscopy (entire large intestine).

Enzyme: a protein that speeds up a chemical reaction. see gastric enzymes

24-hour esophageal pH test: a test used to measure the pH or amount of acid that flows into the esophagus from the stomach during a 24-hour period.

Esophageal manometry test: a test used to measure the strength and muscle coordination of the esophagus during swallowing to identify the source of problems in the upper digestive system.

Esophagus: the "food pipe" leading from the mouth to the stomach.

Esophageal ulcer: a sore or erosion of the esophagus, generally caused by excessive exposure to acid.

Esophagitis: an inflammation, irritation, or ulceration of the lining of the esophagus. This injury is often caused by the excessive exposure of the esophagus to stomach acid.

Esophagus: the tube-like structure that connects the mouth to the stomach and acts as a passageway for food. This organ is one of several that make up the digestive system.

Fats: substances that help the body use some vitamins and keep the skin healthy. They are also the main way the body stores energy.

Fluoroscopy: a continuous X-ray technique that allows the physician to observe how an organ performs its normal function; such as how the esophagus works during swallowing.

Fundus: the upper part of the stomach.

Gallbladder: a pear-shaped reservoir that sits just under the liver. It stores and concentrates bile. During a meal, the gallbladder contracts, sending bile to the duodenum to help absorb and digest fats.

Gastric: pertaining to the stomach.

Gastric enzymes: substances in the stomach and digestive system that break down food. Pepsin is an enzyme in the stomach that breaks down proteins. Lipase is an enzyme produced by the pancreas that breaks down fats in the duodenum. Amylase is also produced by the pancreas, and it breaks down starch. Maltase, sucrase, and lactase are other enzymes secreted in the small intestine to convert certain sugars.

Gastric juice: a mixture (produced by the cells of the stomach) that contains hydrochloric acid and digestive enzymes.

Gastritis: an inflammation of the lining of the stomach from any cause, including infection or alcohol.

Gastroenterologist: a doctor who specializes in disorders and conditions of the gastrointestinal tract.

Gastroesophageal reflux disease (GERD): a digestive condition caused when the acid contents of the stomach regularly back up into the esophagus. Heartburn is the most common symptom of GERD, but regurgitation, difficulty swallowing, and chronic cough, wheezing, hoarseness, and a feeling of a lump in the throat are other symptoms.

Gastroscopy: a procedure performed along with a biopsy to examine the stomach and esophagus using a thin, lighted tube called a gastroscope, which is passed through the mouth and into the stomach.

H2 blockers: a type of medication that is part of a group known as acid blockers or suppressors. These drugs prevent a substance called histamine from stimulating acid production.

Heart attack: permanent damage to the heart muscle caused by a lack of blood supply to the heart for an extended time period. Some of the symptoms of a heart attack are similar to those of heartburn.

Heartburn: a burning discomfort that is generally felt in the chest just behind the breastbone. The burning sensation results when harsh stomach juices come in contact with and irritate the delicate lining of the esophagus. Also known as acid indigestion.

Hernia: the protrusion of part of a structure through the tissues that normally contain it.

Hiatal hernia: a condition that occurs when the upper part of the stomach moves into the chest cavity through a hole in the diaphragm, the muscle separating the stomach from the chest. Hiatal hernias do not cause heartburn, but people with hiatal hernias may be more likely to experience heartburn.

Hiatus: the opening in the diaphragm through which the esophagus passes to the stomach.

Laparoscope: a thin, telescope-like instrument with a miniature video camera and light source used to transmit images to a video monitor during laparoscopic surgery.

Laparoscopic antireflux surgery: a minimally-invasive procedure that corrects GERD by creating an improved valve mechanism at the bottom part of the esophagus.

Laparoscopic surgery: also known as laparoscopy, this is a surgical method that is much less invasive than traditional surgery. Tiny incisions are made to create a passageway for a special instrument called a laparoscope that transmits images to a video monitor. The surgeon watches the video screen while performing the procedure with small instruments that pass through small tubes, or catheters, placed in the incisions.

Large intestine: a 6-foot long muscular tube through which stool, or waste left over from the digestive process, is passed. Undigested food enters the large intestine, where water and salt are absorbed by the intestinal lining. The residue is pressed into feces (stool). When the descending (left) colon becomes full of stool, it empties its contents into the rectum to begin the process of elimination.

Liver: the large organ in the upper right abdomen that performs vital chemical functions, including processing nutrients absorbed from the small intestine; producing and secreting bile; creating sugars, proteins, and fats; detoxifying poisons and converting wastes to urea (a waste product of the breakdown of proteins and the nitrogen-containing compound of urine).

Lower esophageal sphincter (LES): the natural valve that keeps stomach contents in the stomach and out of the esophagus. When working properly, this important valve muscle operates like a door, letting food into the stomach but not back up into the esophagus.

Nausea: a queasy feeling that leads to stomach distress, a distaste for food, and an urge to vomit. Nausea is not a disease, but a symptom of many disorders. It can be brought on by systemic illnesses such as influenza, medications, pain, and inner ear disease.

Nonsteroidal anti-inflammatory drugs (NSAIDs): a class of drugs that are effective at reducing inflammation and pain without steroids. Examples of these drugs include aspirin, naproxen, and ibuprofen.

Manometry test: see esophageal manometry test

Minimally invasive surgery: see laparoscopic surgery

Pancreas: the organ behind the lower part of the stomach. The pancreas, which is about the size of a hand, secretes enzymes into the small intestine to break down protein, fat, and carbohydrate from the food we eat. The pancreas also produces insulin so the body can use glucose (sugar) for energy.

Paraesophageal hernia: a less common type of hiatal hernia in which part of the stomach is pushed or squeezed upward through the diaphragm, moving it next to the lower esophagus. There is no acid reflux with this type of hernia, but there is danger that the stomach could become "strangled," cutting off its blood supply.

Pathology: the study of the characteristics, causes, and effects of a disease.

Peristalsis: the series of involuntary muscular contractions that form a wave-like motion to propel food through the esophagus to the stomach. This same process is used by the intestines to propel digested food and waste.

Promotility agents: prescription medicines used in the treatment of severe heartburn or GERD. These medications help speed gastric emptying, reducing the amount of time that stomach contents stays in the stomach. They also may help strengthen the LES and thereby decrease the amount of stomach acid that can potentially reflux into the esophagus.

Proton pump inhibitors: the most powerful type of acid suppressors. These medications work by preventing acid pumps in the stomach from producing too much acid. Also known as acid pump inhibitors or acid blockers.

Reflux: to flow back or return.

Regurgitation: to expel the contents of the stomach in small amounts, short of vomiting.

Risk factor: a characteristic or event that predisposes a person to a certain condition.

Sliding hernia: the most common type of hiatal hernia that occurs when the lower esophagus and the upper stomach slide into the chest cavity through an opening, or hiatus, in the diaphragm. Heartburn and acid reflux are the result of a sliding hernia.

Small intestine: the portion of the digestive tract that first receives food from the stomach. It is divided into three sections: the duodenum, the jejunum, and the ileum. As food travels through the small intestine, it is further broken down by enzymes, and nutrients from the food are absorbed into the bloodstream.

Sphincter: see lower esophageal sphincter

Stomach: a sac-like organ with muscular walls that holds, mixes, and grinds food. The stomach secretes acid and enzymes that continue the process of breaking down the food.

Stomach (gastric) cancer: a disease in which cancer cells are found in the lining of the stomach. Stomach cancer can develop in any part of the stomach and may spread throughout the stomach to other organs.

Swallowing problems: disorders that may be temporary, or an indication of a serious medical problem. Swallowing disorders have many causes, including nerve and muscle problems, head and neck injuries, and cancer, or they may occur as the result of a stroke. Certain medications — such as antidepressants, antibiotics, heart medications, and some drugs used in chemotherapy for cancer — can contribute to a swallowing problem.

Trocar: a sharp, pointed instrument used to make a puncture incision in the abdominal wall. Used for placement of cannulas.

Ultrasound: a test used to diagnose a wide range of diseases and conditions in which high-frequency sound waves, inaudible to the human ear, are transmitted through body tissues. The echoes vary according to the tissue density. The echoes are recorded and translated into video or photographic images that are displayed on a monitor.

Upper endoscopy: a test used to evaluate the upper digestive system, including the esophagus, stomach and first part of the small intestine called the duodenum. During the test, a thin scope with a light and camera at its tip (endoscope) is used to examine the inside of the upper digestive tract.

Vomiting: the forcible expulsion of the contents of the stomach through the mouth which occurs with symptoms of nausea. Vomiting is not a disease, but rather a symptom of many disorders.

Last reviewed by a Cleveland Clinic medical professional on 12/15/2017.

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