National Digestive Diseases
Information Clearinghouse (NDDIC)

A service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH)

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Digestive Diseases Dictionary L - P


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an enzyme in the small intestine needed to digest milk sugar (lactose).

lactase deficiency
(LAK-tayss) (duh-FISH-en-see)

a lack of the lactase enzyme, causing lactose intolerance.


the sugar found in milk. The body breaks lactose down into galactose and glucose.

lactose intolerance
(LAK-tohss) (in-TOL-ur-uhnss)

being unable to digest lactose, the sugar in milk. This condition occurs when the body cannot produce lactase.

lactose tolerance test
(LAK-tohss) (TOL-ur-uhnss) (test)

a test for lactase deficiency. The patient drinks a liquid that contains milk sugar. Then the patient’s blood is tested to measure the amount of milk sugar in the blood.


a thin tube with a tiny video camera attached that is used to look inside the body to view the surface of organs. See endoscope.

laparoscopic cholecystectomy
(LAP-uh-roh-SKOP-ik) (KOH-lee-siss-TEK-toh-mee)

an operation to remove the gallbladder. The doctor inserts a laparoscope and other surgical instruments through small holes made in the abdomen. The camera allows the doctor to see the gallbladder on a television screen. The doctor removes the gallbladder through the holes.

Drawing of laparoscopic cholecystectomy to remove the gallbladder. A surgeon and assistants are shown holding the laparoscope and viewing the procedure on a monitor.
Laparoscopic cholecystectomy.


a procedure that uses a laparoscope to look at and take tissue from the inside of the body.


an operation that opens up the abdomen.

large intestine
(larj) (in-TESS-tin)

the part of the intestine that includes the appendix, cecum, colon, and rectum. The large intestine absorbs water from stool and changes it from a liquid to a solid form. The large intestine is 5 feet long.


a cleaning of the stomach and colon that uses a special drink and enemas. See bowel prep.


medicines that relieve long-term constipation. Also called cathartics.

lazy colon
(LAY-zee) (KOH-lon)

see atonic colon.

levator syndrome
(leh-VAY-tur) (SIN-drohm)

a feeling of fullness in the anus and rectum with occasional pain caused by muscle spasms.


the largest abdominal organ. The liver carries out many important functions, such as making important blood proteins and bile, changing food into energy, and cleaning alcohol and poisons from the blood.

liver enzyme tests
(LIV-ur) (EN-zym) (tests)

blood tests that may indicate abnormalities of the liver or biliary system. Also called liver function tests.

liver function tests
(LIV-ur) (FUHNK-shuhn) (tests)

see liver enzyme tests.

loop ileostomy
(loop) (IL-ee-OSS-tuh-mee)

a temporary ileostomy in which a loop of the small intestine is pulled through the abdominal wall to create a stoma.

lower esophageal ring
(LOH-wur) (uh-SOF-uh-JEE-uhl) (ring)

an abnormal ring of tissue that may partially block the lower esophagus. Also called Schatzki's ring.

lower esophageal sphincter
(LOH-wur) (uh-SOF-uh-JEE-uhl) (SFINGK-tur)

the muscle between the esophagus and stomach. When a person swallows, this muscle relaxes to let food pass from the esophagus to the stomach. It stays closed at other times to keep stomach contents from flowing back into the esophagus.

Drawing of the lower esophageal sphincter with the esophagus, lower esophageal sphincter, stomach with acid, and small intestine labeled.
Lower esophageal sphincter.

lower GI series
(LOH-wur) (JEE-EYE) (SIHR-eez)

see barium enema x ray.


an obstruction of lymph drainage from the small intestine causing malabsorption.

lymphocytic colitis
(LIM-foh-SIT-ik) (koh-LY-tiss)

an inflammatory bowel disease that affects the large bowel. Also called microscopic colitis because there is no sign of inflammation on the surface of the colon during a colonoscopy.


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magnetic resonance imaging (MRI)
(mag-NET-ik) (REZ-oh-nuhnss) (IM-uhj-ing)

a test that takes pictures of the body's soft tissues. The pictures do not use x rays.

Drawing of a female patient lying in a magnetic resonance imaging machine. Circular magnets surround the patient.
Magnetic resonance imaging.

malabsorption syndromes
(MAL-ab-SORP-shuhn) (SIN-drohmz)

conditions that occur when the small intestine cannot absorb nutrients from foods.

Mallory-Weiss tear
(MAL-uh-ree-WYSS) (tair)

a tear in the lower end of the esophagus caused by severe vomiting.


a condition caused by not eating enough food or not eating a balanced diet.


when the bowel does not rotate completely during embryonic development.


tests that measure muscle pressure and movements in the gastrointestinal tract. See esophageal manometry and rectal manometry.

Meckel's diverticulum
(MEK-uhlz) (DY-vur-TIK-yoo-luhm)

a bulge in the small intestine that is a remnant of the umbilical cord that persists in about 2 percent of people. It can cause bleeding or obstruction.


a huge, swollen colon that results from several different conditions. In children, megacolon is more common in boys than girls. See Hirschsprung disease.


blood in the stool.

Ménétrier disease
(MAYN-ay-tree-AY) (dih-ZEEZ)

a long-term disorder that causes large, coiled folds in the stomach. Also called hypoproteinemic hypertrophic gastritis.


the way cells change food into energy after food is digested and absorbed into the blood.

microvillus inclusion disease
(my-kroh-VIL-uhss) (in-KLOO-zhuhn) (dih-ZEEZ)

a disease characterized by severe diarrhea beginning the first few days after birth. It is life threatening.


the movement of food through the digestive tract.

motility disorders
(moh-TIL-ih-tee) (diss-OR-durz)

see functional disorders.


see magnetic resonance imaging.

mucosal lining
(myoo-KOH-suhl) (LYN-ing)

the lining of gastrointestinal tract organs that absorb nutrients and fluid, form a barrier, and produce mucus.

mucosal protective drugs
(myoo-KOH-suhl) (proh-TEK-tiv) (druhgz)

medicines that protect the stomach lining from acid. Examples are sucralfate and misoprostol. (Brand names: Carafate, Cytotec, Mylanta, Maalox.)

mucous colitis
(MYOO-kuhss) (koh-LY-tiss)

see irritable bowel syndrome.


a clear liquid made by the intestines that coats and protects tissues in the gastrointestinal tract.


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see nonalcoholic steatohepatitis.


the feeling of needing to throw up, or vomit. See vomiting.


death of cells or tissues.

necrotizing enterocolitis
(NEH-kruh-TY-zing) (EN-tur-oh-koh-LY-tiss)

a condition in which part of the tissue in the intestines is destroyed. It occurs mainly in underweight newborns.

neonatal hepatitis
(NEE-oh-NAY-tuhl) (HEP-uh-TY-tiss)

irritation of the liver with no known cause. It occurs in newborns and its symptoms include jaundice and liver cell changes.


new and abnormal growth of tissue that may or may not be cancerous. Also called a tumor.

Nissen fundoplication
(NISS-uhn) (FUN-doh-plih-KAY-shuhn)

an operation to sew the top of the stomach (fundus) around the esophagus. It is used to stop stomach contents from flowing back into the esophagus (reflux) and to repair a hiatal hernia.

Drawings of the stomach and esophagus before the Nissen fundoplication operation, with sutures, and after the Nissen fundoplication operation.
Nissen fundoplication.

nonalcoholic steatohepatitis (NASH)
(NON-al-koh-HOL-ik) (STEE-uh-toh-HEP-uh-TY-tiss)

a common, often “silent,” liver disease that resembles alcoholic liver disease but occurs in people who drink little or no alcohol. The major characteristic of NASH is fat in the liver, along with inflammation and damage.

nontropical sprue
(NON-TRAH-pih-kuhl) (sproo)

see celiac disease.

nonulcer dyspepsia
(NON-UHL-sur) (diss-PEP-see-uh)

constant pain or discomfort in the upper gastrointestinal (GI) tract. Symptoms include burning, nausea, and bloating, but not ulcers. It is a functional disorder.

Norwalk virus
(NOR-wok) (VYruhss)

a virus that may cause gastrointestinal infection and diarrhea. See gastroenteritis.

nutcracker esophagus
(nuht-KRAK-ur) (uh-SOF-uh-guhss)

a condition in which the muscle contraction in the esophagus is too strong, causing chest pain or difficulty swallowing.


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a blockage in the gastrointestinal tract that prevents the flow of liquids or solids.

occult bleeding
(uh-KUHLT) (BLEED-ing)

blood in stool that is not visible to the naked eye. It may be a sign of inflammation or a disease such as colorectal cancer.

oral dissolution therapy
(OR-uhl) (DIH-suh-LOO-shuhn) (THAIR-uh-pee)

an infrequently used method of dissolving cholesterol gallstones. The patient takes the oral medications chenodiol and ursodiol. These medicines are most often used for people who cannot have an operation. (Brand names: Chenix, Actigall.)


drugs that draw fluid into the colon and soften stool, making it easier to pass. This class of drugs is useful for people with idiopathic constipation and includes lactulose and polyethylene glycol electrolyte solution. (Brand names: Cephulac, Miralax.) See laxatives.


a person who has an ostomy. Also called an ostomist in some countries.


an operation that makes it possible for stool to leave the body through an opening made in the abdomen. An ostomy is necessary when part or all of the intestines are removed or blocked. Colostomy and ileostomy are types of ostomy.


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a gland that makes the hormone insulin and enzymes and fluids for digestion.


an irritation of the pancreas that can cause it to stop working. It is most often caused by gallstones or alcohol abuse.

papilla of Vater
(puh-PIL-uh) (uhv) (VAH-tur)

see ampulla of Vater.

papillary stenosis
(PAP-ih-LAIR-ee) (steh-NOH-siss)

a condition in which the openings of the bile ducts and pancreatic ducts narrow.

parenteral nutrition
(puh-REN-tur-uhl) (noo-TRISH-uhn)

a way to provide an intravenous liquid food mixture through a special tube in the chest. Also called hyperalimentation or total parenteral nutrition.

parietal cells
(puh-RY-uh-tuhl) (selz)

cells in the stomach wall that make hydrochloric acid.

pediatric gastroenterologist
(PEE-dee-AT-rik) (GASS-troh-EN-tur-OL-uh-jist)

a doctor who treats children who have digestive diseases.

pelvic pouch

see ileoanal reservoir.


an enzyme made in the stomach that breaks down proteins.


related to the stomach and the duodenum, where pepsin is present.

peptic ulcer
(PEP-tik) (UHL-sur)

a sore in the lining of the esophagus, stomach, or duodenum, usually caused by the bacterium Helicobacter pylori. An ulcer in the stomach is a gastric ulcer; an ulcer in the duodenum is a duodenal ulcer.

Drawing of the stomach and duodenum with the stomach, duodenum, and ulcers labeled.
Peptic ulcers.


the passage of an instrument through the skin to allow access to the organs.

percutaneous transhepatic cholangiography
(PUR-kyoo-TAY-nee-uhss) (TRANZ-heh-PAT-ik) (koh-LAN-jee-OG-ruh-fee)

an x ray of the gallbladder and bile ducts. A dye is injected through the abdomen and liver to make the organs show up on the x ray.

perforated ulcer
(PUR-foh-RAYT-ed) (UHL-sur)

an ulcer that breaks through the wall of the stomach or the duodenum, causing stomach contents to leak into the abdominal cavity.


a hole in the wall of an organ.


the area around the anus.


related to the perineum.


the area between the anus and the sex organs.


a wavelike movement of muscles in the gastrointestinal (GI) tract. Peristalsis moves food and liquid through the GI tract.


the lining of the abdominal cavity.


an infection of the peritoneum.

pernicious anemia
(pur-NISH-uhss) (uh-NEE-mee-uh)

anemia caused by a lack of vitamin B12. The body needs B12 to make red blood cells and nerve cells.

Peutz-Jeghers syndrome
(PUTS-JAY-gurz) (SIN-drohm)

an inherited condition causing many polyps to grow in the intestine. It poses an increased risk of cancer.


the space behind the mouth that serves as a passage for food from the mouth to the esophagus and for air from the nose and mouth to the larynx, or voice box.


a growth on the surface of an organ. People who have polyps in the colon may have an increased risk of colorectal cancer.


the surgical removal of a polyp.


the presence of many polyps.


a group of rare, usually inherited disorders that affect the skin or nervous system and may cause abdominal pain. When a person has porphyria, cells fail to change porphyrins (body chemicals) into heme, the substance that gives blood its red color. Porphyrins then build up in the body and cause illness.

portal hypertension
(POR-tuhl) (HY-pur-TEN-shuhn)

high blood pressure in the portal vein. This vein carries blood into the liver. Portal hypertension is a common complication of cirrhosis and may cause esophageal varices and ascites.

portal vein
(POR-tuhl) (vayn)

the large vein that carries blood from the intestines and spleen to the liver.

portosystemic shunt

an operation to create an opening between the portal vein and other veins around the liver to treat portal hypertension.

postcholecystectomy syndrome
(POST-koh-lee-siss-TEK-toh-mee) (SIN-drohm)

symptoms persisting after removal of the gallbladder or new symptoms caused by its removal.

postgastrectomy syndrome
(POST-gass-TREK-tuh-mee) (SIN-drohm)

a condition that can occur after an operation to remove the stomach (gastrectomy). It causes food to empty too quickly. Also called dumping syndrome or rapid gastric emptying.

postvagotomy stasis
(POST-vay-GOT-uh-mee) (STAY-siss)

delayed stomach emptying, which can occur after surgery affecting the vagus nerve.


  1. a special bag worn over a stoma to collect stool. Also called an ostomy appliance.
  2. an internal, surgically constructed cavity. See ileoanal pouch anastomosis.

primary biliary cirrhosis
(PRY-mair-ee) (BIL-ee-air-ee) (sur-ROH-siss)

a chronic liver disease that slowly destroys the bile ducts in the liver, preventing the release of bile. Long-term irritation of the liver may cause scarring and cirrhosis in later stages of the disease.

primary sclerosing cholangitis
(PRY-mair-ee) (skleh-ROHSS-ing) (KOH-lan-JY-tiss)

irritation, scarring, and narrowing of the bile ducts inside and outside the liver. Bile builds up in the liver and may damage its cells. Many people with this condition also have ulcerative colitis.

proctalgia fugax
(prok-TAL-jee-uh) (FYOO-gaks)

short episodes of intense pain in the rectum. It is caused by muscle spasms around the anus.


an operation to remove the rectum.


irritation of the rectum.


an operation to remove the colon and rectum. Also called coloproctectomy.


irritation of the colon and rectum.


a doctor who specializes in disorders of the anus and rectum.


a short, rigid metal tube used to look into the rectum and anus.


looking into the rectum and anus with a proctoscope.


irritation of the rectum and the sigmoid colon.


an endoscopic examination of the rectum and sigmoid colon. See endoscopy.

prokinetic drugs
(PROH-kih-NET-ik) (druhgz)

medicines that cause muscles in the gastrointestinal tract to move food. Examples are bethanechol and metoclopramide. (Brand names: Duvoid, Reglan.)


a condition that occurs when a body part slips from its normal position.


one of the three main nutrients in food. Foods that provide protein include meat, poultry, fish, cheese, milk, dairy products, eggs, and dried beans. Proteins are also used in the body for cell structure, fighting infection, and other functions. The stomach, small intestine, and pancreas break down proteins into amino acids. After the body's cells use protein, it is broken down into waste products containing nitrogen that must be removed by the kidneys. The blood absorbs amino acids and uses them to build and mend cells. See amino acids.

proton pump inhibitors
(PROHton) (puhmp) (in-HIB-ih-turz)

medicines that stop the stomach's acid pump. Examples include omeprazole, lansoprazole, and esomeprazole. (Brand names: Prilosec, Prevacid, Nexium.)

pruritus ani
(proo-RY-tuhss) (AY-nee)

itching around the anus.

pseudomembranous colitis
(SOO-doh-MEM-bruh-nuhss) (koh-LY-tiss)

severe irritation of the colon caused by Clostridium difficile bacterium. It occurs after taking oral antibiotics, which kill bacteria that normally live in the colon.

pyloric sphincter
(py-LOR-ik) (SFINGK-tur)

the muscle between the stomach and the small intestine.

pyloric stenosis
(py-LOR-ik) (steh-NOH-siss)

a narrowing of the opening between the stomach and the small intestine.


an operation to widen the opening between the stomach and the small intestine, which allows stomach contents to pass more freely from the stomach.


the opening from the stomach into the top of the small intestine (duodenum).

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Page last updated May 10, 2012

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