Gastroenterology is the study of the gastrointestinal (GI) tract of the body. A gastroenterologist diagnoses and treats diseases of the digestive organs, including the stomach, esophagus, intestines, pancreas, liver and gallbladder. This specialist treats conditions such as abdominal pain, nausea and vomiting, ulcers, diarrhea, cancer in the GI tract, and jaundice. A gastroenterologist also performs complex diagnostic procedures, including the use of endoscopes to see and treat internal organs.

Physicians in this specialty treat patients suffering from numerous diseases and illnesses, but some of the most common are Hemorrhoids, Hiatal Hernia, Digestive Disorders, heartburn, Rectal Bleeding, Ulcer, Ostomy Care, Polyps, colon cancer, Crohn's Disease, Diarrhea, Abdominal Pain, Constipation, acid reflux, Bowel Diseases, cystic fibrosis, Ulcerative Colitis, Nausea, Appendicitis, and Colitis.

Once properly diagnosed, practitioners can perform numerous procedures on patients including GERD Services, abdominal surgery, Appendectomy, Cholecystectomy, laparoscopy, Liver Transplantation, and Cholecystography.

To diagnose patients with possible illnesses and diseases, specialists will often perform one of many tests including endoscopy, Colonoscopy, Barium Enema, Liver Biopsy, Sigmoidoscopy, Barium Swallow, Abdominal Ultrasound, Esophagogastroduodenoscopy (EGD), Gallbladder Scan, Upper Gastrointestinal Series, Endoscopic Retrograde Cholangiopancreatography, Radiographic X-Ray, Proctoscopy, Pancreas Scan, Abdominal Angiogram, Anoscopy, Liver Scan, and Abdominal X-rays.

Doctor density varies by specialty and location. Illinois has 642 practicing gastroenterologists. Broken out by city, gastroenterology doctor density in Algonquin is 12, in Alton is 5, in Aurora is 12, in Belleville is 9, in Benton is 1, in Berwyn is 5, in Bloomington is 12, in Blue Island is 2, in Breese is 1, in Burbank is 4, in Cairo is 1, in Calumet City is 4, in Canton is 1, in Carbondale is 3, in Centralia is 1, in Champaign is 4, in Chicago is 244, in Chicago Heights is 5, in Chillicothe is 1, in Cicero is 3, in Clinton is 1, in Crystal Lake is 3, in Danville is 4, in Darien is 1, in Decatur is 5, in Des Plaines is 7, in Dixon is 4, in Du Quoin is 1, in Edwardsville is 1, in Elgin is 15, in Elmhurst is 14, in Eureka is 2, in Evanston is 19, in Fox River Grove is 5, in Freeport is 2, in Galesburg is 1, in Geneseo is 2, in Geneva is 17, in Glen Ellyn is 4, in Granite City is 4, in Harvard is 1, in Harvey is 2, in Herrin is 2, in Hickory Hills is 1, in Highland Park is 14, in Hoffman Estates is 17, in Jerseyville is 2, in Joliet is 12, in Kankakee is 1, in Kewanee is 1, in Lake Forest is 6, in Lincoln is 2, in Loves Park is 1, in Martinsville is 2, in Mattoon is 7, in Maywood is 22, in Mchenry is 10, in Moline is 14, in Morris is 5, in Morton Grove is 2, in Mount Vernon is 1, in Naperville is 29, in Normal is 8, in North Chicago is 3, in Oak Forest is 4, in Oakbrook Terrace is 5, in Ottawa is 2, in Palos Heights is 10, in Pana is 1, in Paris is 1, in Park Ridge is 14, in Pekin is 2, in Peoria is 16, in Peru is 3, in Pittsfield is 1, in Pontiac is 1, in Princeton is 3, in Prospect Heights is 1, in Quincy is 4, in Red Bud is 1, in Rock Island is 3, in Rockford is 25, in Rossville is 1, in Sandwich is 1, in Silvis is 2, in Spring Valley is 1, in Springfield is 15, in Sterling is 3, in Sycamore is 3, in Taylorville is 1, in Urbana is 5, in Washington is 1, in Waterloo is 2, in Watseka is 2, in Waukegan is 2, in Westchester is 2, in Wheaton is 5, in Woodstock is 7, in Yorkville is 1, and in Zion is 1.

Most people think that Chicago, because of its size and popularity, is Illinois’ capital city, but that distinction belongs to Springfield, home of the Abraham Lincoln Museum. Illinois has hundreds of museums, numerous yearly art and ethnic festivals, a lakeshore bordering Lake Michigan, and the many national forests and parks that offers visitors camping, horseback riding, biking, kayaking, and fishing. Chicago is home to the Sears Tower, the Shedd Aquarium, the Art Institute of Chicago, the Adler Planetarium, the Museum of Science and Industry, and other cultural opportunities and restaurants in the Navy Pier area.

According to 2005 Census estimates, Illinois has a population of 12,763,371. Of this population, 3,172,677 are under the age of 18 and 1,523,937 are at or above the age of 65.