Diagnosing Irritable Bowel Syndrome (IBS) / Spastic Colon
Spastic Colon or IBS is a functional disorder that is poorly understood and therefore difficult to control. The two main variants are diarrhea predominant and constipation predominant spastic colon.
It is important to exclude other more serious causes, especially in older persons, by getting diagnosed.
The Rome II guidelines are used in diagnosing Spastic Colon. There being no medical tests to positively identify it, the diagnosis of Spastic Colon / IBS is a process of exclusion.
Diagnosing Spastic Colon IBS
Some of the diseases that have to be excluded are:
Colon cancer
Ovarian cancer
Inflammatory bowel diseases (Crohn's and Ulcerative Colitis)
Diverticulosis / Diverticulitis
Celiac (a genetic, autoimmune disorder resulting in gluten intolerance)
Endometriosis
Bacterial infections
Intestinal parasites
Gallstones
Food allergies
Depending on medical history, age and symptoms, doctors may do tests to eliminate other diseases that could cause symptoms similar to that of Spastic Colon IBS. These tests include:
- Blood tests
- Urine analysis
- Liver function tests
- Rectal exam
- Abdominal x-rays
- Stool sample, to check for blood or evidence of infection.
- Sigmoidoscopy, in which a flexible, lighted tube with a tiny camera on the end is inserted into the rectum and up the left side of the colon, or a colonoscopy, in which a longer tube examines the entire colon to look for internal abnormalities.
- Barium X-ray, in which a chalky solution is swallowed or pumped into the rectum to coat the inside of the gastrointestinal tract and highlight abnormalities.
- For women, a gynecological exam including CA-125 blood test for ovarian cancer.
- Asking you to stop eating or drinking certain foods for up to three weeks to determine if your diet is contributing to your symptoms (for example, lactose intolerance).
Other tests required to diagnose IBS should be minimal and will depend on the symptom subtype. This could include:
- Diarrhea-predominant symptoms, a small bowel radiograph or lactose/dextrose H2 breath test.
- Numbness in association with constipation, Multiple Sclerosis should be excluded.
- Pain as a predominant symptom, an abdominal radiograph during an acute episode.
- Indigestion, nausea and bloating. An abdominal ultrasound to rule out gallstones.
- In patients over 50 pancreatic cancer may need to be excluded.

