ACG CxA key terms

Undetectable hepatitis C virus RNA in the blood at a defined interval after completing antiviral therapy, typically 12 or 24 weeks. It is used as the operational definition of cure for hepatitis C.

A class of oral drugs that block specific hepatitis C viral proteins such as the NS5B polymerase or NS5A protein, achieving high cure rates with short, well-tolerated regimens across genotypes.

A prognostic score calculated from bilirubin, INR, creatinine, and sodium that estimates short-term mortality in chronic liver disease and is used to prioritize patients for liver transplantation.

A reversible neuropsychiatric syndrome caused by impaired hepatic clearance of gut-derived toxins, chiefly ammonia, producing confusion, asterixis, and altered consciousness in patients with cirrhosis or portosystemic shunting.

Abnormal accumulation of fluid within the peritoneal cavity, most often caused by portal hypertension from cirrhosis. It is evaluated with diagnostic paracentesis and managed with sodium restriction, diuretics, and large-volume paracentesis.

Infection of ascitic fluid without an obvious intra-abdominal source, diagnosed when the ascitic neutrophil count exceeds 250 cells per microliter. It requires prompt antibiotics and is often followed by secondary prophylaxis.

Advanced liver fibrosis with regenerative nodules and distorted architecture, producing portal hypertension and impaired synthetic function. It is staged clinically by complications such as ascites, variceal bleeding, and encephalopathy.

A noninvasive imaging technique that measures liver stiffness to estimate fibrosis, using either vibration-controlled transient elastography or shear-wave ultrasound. Results are interpreted alongside clinical context because inflammation and congestion can falsely elevate values.

A validated noninvasive index combining age, body mass index, glucose, platelets, albumin, and aminotransferase ratios to estimate the likelihood of advanced fibrosis in patients with metabolic fatty liver disease.

Functional acute kidney injury in advanced liver disease caused by splanchnic vasodilation and renal vasoconstriction, occurring without structural kidney damage and often triggered by infection or volume loss.

An endoscopic therapy in which rubber bands are placed around esophageal varices to cause thrombosis and obliteration. It is used both to treat acute variceal hemorrhage and for secondary prophylaxis.

Endoscopic examination of the esophagus, stomach, and proximal duodenum using a flexible video endoscope, used for diagnosing mucosal disease, obtaining biopsies, and performing therapeutic interventions such as hemostasis or dilation.

A combined endoscopic and fluoroscopic procedure using a side-viewing duodenoscope to cannulate the biliary and pancreatic ducts for diagnosis and therapy, including stone removal and stent placement.

The most common serious complication of ERCP, presenting as new or worsened abdominal pain with elevated pancreatic enzymes after the procedure. Risk is reduced with rectal NSAIDs, hydration, and selective cannulation technique.

Endoscopic incision of the biliary or pancreatic sphincter during ERCP to facilitate stone extraction, stent placement, or drainage. Bleeding and perforation are recognized procedural risks.

Administration of sedative and analgesic agents, typically benzodiazepines and opioids, to produce a depressed level of consciousness during endoscopy while preserving the ability to respond to verbal commands and maintain a patent airway.

Endoscopic visualization of the entire colon and terminal ileum with a flexible colonoscope, used for colorectal cancer screening, polyp removal, and evaluation of lower gastrointestinal symptoms.

The proportion of screening colonoscopies in which at least one adenoma is removed. It is a validated quality indicator for colonoscopy performance, with higher rates associated with lower interval cancer risk.

The cleansing regimen of dietary restriction and laxative solution taken before colonoscopy to clear stool from the colon, which directly affects mucosal visualization, adenoma detection, and procedural safety.

A colorectal cancer diagnosed after a screening test but before the next recommended screening examination, often reflecting missed lesions or incomplete bowel cleansing at the prior colonoscopy.

The percentage of colonoscopies in which the endoscope reaches the cecum, a quality measure reflecting procedural completeness and technical skill. It is typically tracked alongside withdrawal time and adenoma detection rate.

A group of chronic immune-mediated disorders of the gastrointestinal tract, chiefly Crohn disease and ulcerative colitis, characterized by relapsing inflammation and requiring long-term medical and sometimes surgical management.

A chronic transmural inflammatory bowel disease that can affect any part of the gastrointestinal tract from mouth to anus, often with skip lesions, fistulas, and strictures, and frequently involving the terminal ileum.

A chronic inflammatory bowel disease limited to the colonic mucosa, beginning in the rectum and extending proximally in a continuous pattern, with symptoms of bloody diarrhea, urgency, and tenesmus.

A neutrophil-derived protein measured in stool that serves as a noninvasive marker of intestinal inflammation, useful for distinguishing inflammatory bowel disease from irritable bowel syndrome and for monitoring disease activity.

Endoscopic resolution of visible inflammation and ulceration in inflammatory bowel disease, now a key treatment target because it predicts sustained remission and reduced risk of surgery and hospitalization.

Treatment with agents that target specific components of the immune inflammatory cascade, such as tumor necrosis factor or integrin molecules, used in moderate to severe inflammatory bowel disease and often requiring infection screening before initiation.

A functional bowel disorder defined by recurrent abdominal pain related to defecation or changes in stool form, without structural disease, and classified into constipation-predominant, diarrhea-predominant, or mixed subtypes.

Consensus symptom-based diagnostic criteria for functional gastrointestinal disorders, defining conditions such as irritable bowel syndrome by the duration and pattern of symptoms in the absence of alarm features.

A disorder of chronic postprandial fullness, early satiety, or epigastric pain without identifiable organic cause, often related to impaired gastric accommodation or delayed emptying and managed with acid suppression and neuromodulators.

Delayed gastric emptying without mechanical obstruction, presenting with nausea, vomiting, early satiety, and bloating. It is confirmed by gastric emptying testing and can complicate diabetes or follow certain surgeries.

A scintigraphic test that measures the rate at which a standardized radiolabeled meal leaves the stomach, used to confirm delayed gastric emptying when gastroparesis is suspected.

A structured elimination diet restricting fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, followed by systematic reintroduction, used to reduce bloating and abdominal pain in irritable bowel syndrome.

An immune-mediated enteropathy triggered by dietary gluten that causes small intestinal villous atrophy and malabsorption, diagnosed with serologic testing and duodenal biopsy while the patient is still consuming gluten.

A viral envelope protein detected in blood that indicates current hepatitis B infection, whether acute or chronic. Its persistence beyond six months defines chronic hepatitis B.

Replacement of normal distal esophageal squamous mucosa by intestinal-type columnar epithelium due to chronic acid reflux, a premalignant condition requiring surveillance endoscopy for dysplasia and adenocarcinoma.

A condition in which reflux of gastric contents produces troublesome symptoms or mucosal injury, managed with lifestyle measures, acid suppression, and sometimes antireflux surgery or endoscopic therapy.

The principle of ensuring fair access to high-quality gastrointestinal and liver care by identifying and reducing disparities related to race, ethnicity, income, geography, language, and insurance status.

The nonmedical conditions in which people live and work, including income, housing, transportation, and education, that shape access to screening, treatment adherence, and outcomes in digestive and liver disease.

Systematic testing of average-risk adults to detect colorectal cancer or its precursors, using colonoscopy or stool-based tests, with the goal of reducing incidence and mortality through timely follow-up of abnormal results.