What it is (overview)

An XR barium enema (also called a barium enema X-ray or lower GI series) is an imaging test that uses X-rays to look closely at the lining and shape of the rectum and colon (large intestine). During the test, a white liquid called barium sulfate is gently introduced into the lower gastrointestinal tract through the rectum. Barium coats the inside of the colon so it shows up clearly on X-ray images, making it easier to see changes in the bowel wall or the outline of the colon.

Some exams use an air-contrast (double-contrast) technique, where a small amount of air is added after the barium. The air helps spread the barium into a thin layer and can improve the ability to detect small surface changes such as polyps.

This test does not measure a “blood level” like a lab test. Instead, it provides pictures that can show:

• Normal findings: A smooth, evenly shaped colon and rectum without suspicious narrowings, masses, or filling defects.
• Possible abnormal findings: Areas that look like a growth (possible tumors), rounded shadows projecting into the barium (possible polyps), narrowed segments (a “stricture”), outpouchings (diverticula), or signs of inflammation that may suggest inflammatory bowel disease.

Your clinician will interpret the results along with your symptoms and medical history. If the barium enema suggests an abnormality, a follow-up test—often colonoscopy or CT imaging—may be recommended to confirm the finding and, when needed, take a biopsy.

When & why it's usually done

A doctor may order a barium enema when there are symptoms pointing to a problem in the colon or rectum, especially if another test is not suitable or if more detail is needed. Common reasons include ongoing or unexplained:

• Abdominal pain or cramping
• Changes in bowel habits (new constipation, diarrhea, or alternating patterns)
• Blood in the stool or rectal bleeding
• Unexplained mucus in stool
• Unintended weight loss or unexplained anemia that raises concern for colon disease

It may also be used to evaluate or help rule out conditions such as:

• Suspected colon tumors or large polyps
• Possible inflammatory bowel disease (such as ulcerative colitis or Crohn’s disease affecting the colon)
• Suspected strictures (narrowed areas) that may cause blockage symptoms like bloating or difficulty passing stool
• Diverticular disease (small pouches in the colon wall)

In modern practice, colonoscopy and CT colonography are often used for many colon evaluations, but a barium enema can still be helpful in certain settings (for example, when colonoscopy cannot be completed or is not advised). Your care team will choose the most appropriate imaging test based on your symptoms, age, risk factors, and overall health.

Common diseases related to it

• Colorectal cancer (colon or rectal tumors)
• Colon polyps (including adenomatous polyps)
• Inflammatory bowel disease (ulcerative colitis, Crohn’s colitis)
• Diverticulosis and diverticular disease
• Colonic strictures (from inflammation, scarring, or other causes)
• Colitis (including ischemic or infectious colitis, when suspected clinically)
• Volvulus (twisting of the colon, in selected cases)
• Intussusception (more common in children; evaluated case-by-case)

Health goals where it may help

• Finding a cause of persistent abdominal pain, bloating, or discomfort
• Evaluating concerning changes in bowel habits to support earlier diagnosis and treatment
• Investigating blood in stool or rectal bleeding to identify potential sources
• Assessing the colon and rectum for suspected polyps or tumors when endoscopy is incomplete or not possible
• Monitoring known or suspected inflammatory bowel disease and checking for complications such as narrowing
• Checking for structural problems (diverticula, strictures, abnormal colon shape) that may contribute to constipation or obstruction symptoms