Manometry: Measurement of the pressure or tension of liquids or gases with a manometer.Esophageal Motility Disorders: Disorders affecting the motor function of the UPPER ESOPHAGEAL SPHINCTER; LOWER ESOPHAGEAL SPHINCTER; the ESOPHAGUS body, or a combination of these parts. The failure of the sphincters to maintain a tonic pressure may result in gastric reflux of food and acid into the esophagus (GASTROESOPHAGEAL REFLUX). Other disorders include hypermotility (spastic disorders) and markedly increased amplitude in contraction (nutcracker esophagus).Sphincter of Oddi: The sphincter of the hepatopancreatic ampulla within the duodenal papilla. The COMMON BILE DUCT and main pancreatic duct pass through this sphincter.Esophagus: The muscular membranous segment between the PHARYNX and the STOMACH in the UPPER GASTROINTESTINAL TRACT.Peristalsis: A movement, caused by sequential muscle contraction, that pushes the contents of the intestines or other tubular organs in one direction.Deglutition: The act of taking solids and liquids into the GASTROINTESTINAL TRACT through the mouth and throat.Anal Canal: The terminal segment of the LARGE INTESTINE, beginning from the ampulla of the RECTUM and ending at the anus.Esophageal Achalasia: A motility disorder of the ESOPHAGUS in which the LOWER ESOPHAGEAL SPHINCTER (near the CARDIA) fails to relax resulting in functional obstruction of the esophagus, and DYSPHAGIA. Achalasia is characterized by a grossly contorted and dilated esophagus (megaesophagus).Esophageal Spasm, Diffuse: A hypermotility disorder of the ESOPHAGUS that is characterized by spastic non-peristaltic responses to SWALLOWING; CHEST PAIN; and DYSPHAGIA.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Esophageal Sphincter, Lower: The physiologic or functional barrier to GASTROESOPHAGEAL REFLUX at the esophagogastric junction. Sphincteric muscles remain tonically contracted during the resting state and form the high-pressure zone separating the lumen of the ESOPHAGUS from that of the STOMACH. (Haubrich et al, Bockus Gastroenterology, 5th ed., pp399, 415)Esophageal Sphincter, Upper: The structure at the pharyngoesophageal junction consisting chiefly of the CRICOPHARYNGEUS MUSCLE. It normally occludes the lumen of the ESOPHAGUS, except during SWALLOWING.Esophageal pH Monitoring: Analysis of the HYDROGEN ION CONCENTRATION in the lumen of the ESOPHAGUS. It is used to record the pattern, frequency, and duration of GASTROESOPHAGEAL REFLUX.Esophagogastric Junction: The area covering the terminal portion of ESOPHAGUS and the beginning of STOMACH at the cardiac orifice.Gastroesophageal Reflux: Retrograde flow of gastric juice (GASTRIC ACID) and/or duodenal contents (BILE ACIDS; PANCREATIC JUICE) into the distal ESOPHAGUS, commonly due to incompetence of the LOWER ESOPHAGEAL SPHINCTER.Gastrointestinal Motility: The motor activity of the GASTROINTESTINAL TRACT.Deglutition Disorders: Difficulty in SWALLOWING which may result from neuromuscular disorder or mechanical obstruction. Dysphagia is classified into two distinct types: oropharyngeal dysphagia due to malfunction of the PHARYNX and UPPER ESOPHAGEAL SPHINCTER; and esophageal dysphagia due to malfunction of the ESOPHAGUS.Esophageal Diseases: Pathological processes in the ESOPHAGUS.Common Bile Duct Diseases: Diseases of the COMMON BILE DUCT including the AMPULLA OF VATER and the SPHINCTER OF ODDI.Fecal Incontinence: Failure of voluntary control of the anal sphincters, with involuntary passage of feces and flatus.Diagnostic Techniques, Digestive System: Methods and procedures for the diagnosis of diseases or dysfunction of the digestive system or its organs or demonstration of their physiological processes.Constipation: Infrequent or difficult evacuation of FECES. These symptoms are associated with a variety of causes, including low DIETARY FIBER intake, emotional or nervous disturbances, systemic and structural disorders, drug-induced aggravation, and infections.Defecation: The normal process of elimination of fecal material from the RECTUM.Rectum: The distal segment of the LARGE INTESTINE, between the SIGMOID COLON and the ANAL CANAL.Myoelectric Complex, Migrating: A pattern of gastrointestinal muscle contraction and depolarizing myoelectric activity that moves from the stomach to the ILEOCECAL VALVE at regular frequency during the interdigestive period. The complex and its accompanying motor activity periodically cleanse the bowel of interdigestive secretion and debris in preparation for the next meal.Postcholecystectomy Syndrome: Abdominal symptoms after removal of the GALLBLADDER. The common postoperative symptoms are often the same as those present before the operation, such as COLIC, bloating, NAUSEA, and VOMITING. There is pain on palpation of the right upper quadrant and sometimes JAUNDICE. The term is often used, inaccurately, to describe such postoperative symptoms not due to gallbladder removal.Gastrointestinal Transit: Passage of food (sometimes in the form of a test meal) through the gastrointestinal tract as measured in minutes or hours. The rate of passage through the intestine is an indicator of small bowel function.Fundoplication: Mobilization of the lower end of the esophagus and plication of the fundus of the stomach around it (fundic wrapping) in the treatment of GASTROESOPHAGEAL REFLUX that may be associated with various disorders, such as hiatal hernia. (From Dorland, 28th ed)Sphincter of Oddi Dysfunction: Organic or functional motility disorder involving the SPHINCTER OF ODDI and associated with biliary COLIC. Pathological changes are most often seen in the COMMON BILE DUCT sphincter, and less commonly the PANCREATIC DUCT sphincter.Intestinal Pseudo-Obstruction: A type of ILEUS, a functional not mechanical obstruction of the INTESTINES. This syndrome is caused by a large number of disorders involving the smooth muscles (MUSCLE, SMOOTH) or the NERVOUS SYSTEM.Fluoroscopy: Production of an image when x-rays strike a fluorescent screen.Transducers, Pressure: Transducers that are activated by pressure changes, e.g., blood pressure.Technetium Tc 99m Disofenin: A radiopharmaceutical used extensively in cholescintigraphy for the evaluation of hepatobiliary diseases. (From Int Jrnl Rad Appl Inst 1992;43(9):1061-4)Pharynx: A funnel-shaped fibromuscular tube that conducts food to the ESOPHAGUS, and air to the LARYNX and LUNGS. It is located posterior to the NASAL CAVITY; ORAL CAVITY; and LARYNX, and extends from the SKULL BASE to the inferior border of the CRICOID CARTILAGE anteriorly and to the inferior border of the C6 vertebra posteriorly. It is divided into the NASOPHARYNX; OROPHARYNX; and HYPOPHARYNX (laryngopharynx).Monitoring, Ambulatory: The use of electronic equipment to observe or record physiologic processes while the patient undergoes normal daily activities.Rectal Prolapse: Protrusion of the rectal mucous membrane through the anus. There are various degrees: incomplete with no displacement of the anal sphincter muscle; complete with displacement of the anal sphincter muscle; complete with no displacement of the anal sphincter muscle but with herniation of the bowel; and internal complete with rectosigmoid or upper rectum intussusception into the lower rectum.Electric Impedance: The resistance to the flow of either alternating or direct electrical current.Fissure in Ano: A painful linear ulcer at the margin of the anus. It appears as a crack or slit in the mucous membrane of the anus and is very painful and difficult to heal. (Dorland, 27th ed & Stedman, 25th ed)Hernia, Hiatal: STOMACH herniation located at or near the diaphragmatic opening for the ESOPHAGUS, the esophageal hiatus.Esophagoscopy: Endoscopic examination, therapy or surgery of the esophagus.Ampulla of Vater: A dilation of the duodenal papilla that is the opening of the juncture of the COMMON BILE DUCT and the MAIN PANCREATIC DUCT, also known as the hepatopancreatic ampulla.Chest Pain: Pressure, burning, or numbness in the chest.Speech, Esophageal: A method of speech used after laryngectomy, with sound produced by vibration of the column of air in the esophagus against the contracting cricopharyngeal sphincter. (Dorland, 27th ed)Spasm: An involuntary contraction of a muscle or group of muscles. Spasms may involve SKELETAL MUSCLE or SMOOTH MUSCLE.Esophagitis, Peptic: INFLAMMATION of the ESOPHAGUS that is caused by the reflux of GASTRIC JUICE with contents of the STOMACH and DUODENUM.Rectal Diseases: Pathological developments in the RECTUM region of the large intestine (INTESTINE, LARGE).Gastric Emptying: The evacuation of food from the stomach into the duodenum.Butylscopolammonium Bromide: Antimuscarinic quaternary ammonium derivative of scopolamine used to treat cramps in gastrointestinal, urinary, uterine, and biliary tracts, and to facilitate radiologic visualization of the gastrointestinal tract.Surgical Stapling: A technique of closing incisions and wounds, or of joining and connecting tissues, in which staples are used as sutures.Megacolon: Dilatation of the COLON, often to alarming dimensions. There are various types of megacolon including congenital megacolon in HIRSCHSPRUNG DISEASE, idiopathic megacolon in CONSTIPATION, and TOXIC MEGACOLON.Dilatation: The act of dilating.Duodenum: The shortest and widest portion of the SMALL INTESTINE adjacent to the PYLORUS of the STOMACH. It is named for having the length equal to about the width of 12 fingers.Sphincterotomy, Endoscopic: Incision of Oddi's sphincter or Vater's ampulla performed by inserting a sphincterotome through an endoscope (DUODENOSCOPE) often following retrograde cholangiography (CHOLANGIOPANCREATOGRAPHY, ENDOSCOPIC RETROGRADE). Endoscopic treatment by sphincterotomy is the preferred method of treatment for patients with retained or recurrent bile duct stones post-cholecystectomy, and for poor-surgical-risk patients that have the gallbladder still present.Digestive System Surgical Procedures: Surgery performed on the digestive system or its parts.Defecography: Radiographic examination of the process of defecation after the instillation of a CONTRAST MEDIA into the rectum.Gastrointestinal Agents: Drugs used for their effects on the gastrointestinal system, as to control gastric acidity, regulate gastrointestinal motility and water flow, and improve digestion.Technetium Tc 99m Lidofenin: A nontoxic radiopharmaceutical that is used in RADIONUCLIDE IMAGING for the clinical evaluation of hepatobiliary disorders in humans.Cholecystectomy: Surgical removal of the GALLBLADDER.Diverticulum, Esophageal: Saccular protrusion beyond the wall of the ESOPHAGUS.Eructation: The ejection of gas or air through the mouth from the stomach.Anti-Dyskinesia Agents: Drugs used in the treatment of movement disorders. Most of these act centrally on dopaminergic or cholinergic systems. Among the most important clinically are those used for the treatment of Parkinson disease (ANTIPARKINSON AGENTS) and those for the tardive dyskinesias.Encopresis: Incontinence of feces not due to organic defect or illness.Larynx, Artificial: A device, activated electronically or by expired pulmonary air, which simulates laryngeal activity and enables a laryngectomized person to speak. Examples of the pneumatic mechanical device are the Tokyo and Van Hunen artificial larynges. Electronic devices include the Western Electric electrolarynx, Tait oral vibrator, Cooper-Rand electrolarynx and the Ticchioni pipe.Pyloric Antrum: The region between the sharp indentation at the lower third of the STOMACH (incisura angularis) and the junction of the PYLORUS with the DUODENUM. Pyloric antral glands contain mucus-secreting cells and gastrin-secreting endocrine cells (G CELLS).Esophagitis: INFLAMMATION, acute or chronic, of the ESOPHAGUS caused by BACTERIA, chemicals, or TRAUMA.Heartburn: Substernal pain or burning sensation, usually associated with regurgitation of gastric juice into the esophagus.