GI surgeries are divided into two:

• Upper gastrointestinal (GI) surgeries: The upper GI tract is made up of mouth, oesophagus, stomach and duodenum. Upper GI series also are known as barium swallow which involves the use of X-rays and fluoroscopy. The internal organs and their movements are visualised on a video monitor.
• Lower gastrointestinal (GI) surgeries: The lower GI tract consists of the large intestine, small intestine and the anus. A barium enema along with an x-ray will be done to examine the problems of the large intestine.

GI series help diagnose the cause of abdominal pain, difficulty swallowing, nausea, vomiting and unexplained loss of weight. The medical history of the patient is examined before the procedure. GI series does not require anaesthesia and takes about 2 to 5 hours to complete. It is only when the barium moves slowly that it might take longer to complete.

Oesophageal varices, abnormal growths, strictures, gastroesophageal reflux, hiatal hernia and ulcers are all detected in the upper GI series. The upper GI tract is cleared of any food and drink that is found in the lining of the organs. Upper GI surgeries may include pancreaticoduodenectomy, oesophagectomy, liver resection, and so on.

Lower GI series will diagnose cancerous growths, diverticula, fistula (both internal and external), swelling or inflammation of the intestine, intestinal bleeding, polyps, ulcers on the lining of the intestine. Lower GI series involves bowel cleansing where the patient is prescribed a clear liquid diet 1–3 days prior to the procedure. Lower GI surgeries involve colorectal surgery and surgery of the small intestine (low or ultra-low rectal cancer resections).