A lower gastrointestinal series is a medical procedure used to examine and diagnose problems with the human colon of the large intestine. Radiographs (X-ray pictures) are taken while barium sulfate, a radiocontrast agent, fills the colon via an enema through the rectum.
The term barium enema usually refers to a lower gastrointestinal series, although enteroclysis (an upper gastrointestinal series) is often called a small bowel barium enema.
Purpose
For any suspected large bowel disease, colonoscopy is the investigation of choice because tissue sample can be taken for investigation. Virtual colonoscopy (also known as CT colonography) is another preferred investigation, provided that facilities and expertise are available. Virtual colonoscopy also avoids the risk of total blockage of any stricture in the large bowel due to barium impaction. Some conditions are absolutely contraindicated for barium enema namely: toxic megacolon, pseudomembranous colitis, and recent history rigid endoscopy of the large bowel in the past five days and recent history of flexible endoscopy in the past 24 hours. This is because, rigid endoscopy tends to use larger biopsy forceps to take tissue samples from the bowel wall while flexible endoscopy uses small biopsy forceps to take superficial samples.
Other views include right and left decubitus views