A colonoscopy is a test carried out in order to examine the rectum and the entire length of the large intestine (also known as the colon). In most cases, the test examines the last part of the small intestine as well. Similar to other pediatric endoscopic tests, colonoscopies are performed under deep sedation, usually administered by an anesthesiologist. During the test, a doctor inserts a flexible tube (at the end of which is a tiny camera) into the patient's anus in order to identify the location, type and severity of problems such as inflammation, bleeding or polyps. After 8-10 years with colitis, this test should be administered every 1-3 years to identify pre-malignant changes related to the chronic inflammation, if any have developed. The doctor will provide instructions for clearing the intestine prior to the test. 

A sigmoidoscopy is a similar but much shorter test, examining only the rectum and the end of the colon, known as the sigmoid. This shorter test suffices when there is a need for a general assessment of the severity of the disease, such as evaluation of a course of treatment or when atypical symptoms occur.

A gastroscopy is a test carried out in order to examine the esophagus, stomach and duodenum (first part of the small intestine). During the test, a doctor inserts a flexible tube (at the end of which is a tiny camera) into the patient's stomach through the mouth. The test can assist in identifying inflammatory involvement of the upper intestine, which in some cases could imply Crohn's disease. In children, gastroscopy serves as a routine examination in assessing IBD. With regard to adults, the test is usually performed when focal symptoms are present.

A regular abdominal X-ray
Abdominal x-rays do not play a significant role in diagnosing IBD though there are some clues to be inferred from an X-ray that could support diagnosis. X-rays are used in assessing acute exacerbations of Crohn's when intestinal blockage or intestinal perforation are suspected, and in severe ulcerative colitis for diagnosing complications such as toxic dilatation of the bowel.

"Passage" - small intestine follow-through examination using contrast solution
This test is carried out in order to visualize the small intestine, the vast majority of which is not covered by colonoscopy and gastroscopy. Before the test, the patient drinks a contrast solution and for the following 2-3 hours a radiologist follows the progression of the solution until it reaches the colon. The test could visualize inflammation typical to Crohn's disease as well as assisting in pinpointing the precise location and nature of the disease (such as a narrowing of the intestine or small intestine fistula resulting from the disease). This information is valuable for diagnosis, planning of treatment and assessing future risks posed by the inflammation. The examination has several disadvantages: it involves radiation, its degree of precision depends on the examiner's skills and it does not visualize the colon. The degree of precision of the test is lower than CTE and MRE (see below).

Barium Enema
To complement the Passage test, this examination uses contrast solution inserted into the rectum to visualize the large bowel (colon). The test visualizes the colon well but with the expansion in usage of endoscopic technologies enabling a clearer view of the tissue as well as sampling biopsies when necessary, barium enemas are becoming a much less frequent choice.

Computed Tomography Enterography (CTE)
This test creates a 3-D image of body organs using X-ray technology. This technology has improved significantly in recent years to the point that its current resolution is of such high quality that the lining of the intestine can be visualized better than with a traditional radiography test (Passage). Thus, the entire small intestine can be visualized, facilitating more precise diagnosis and characterization of the disease. Furthermore, the test also provides a very good visualization of all the abdominal organs. This allows for diagnosing fistulas, abscesses, free fluids and other pathologies. The prominent disadvantage of this examination is the large amount of radiation entailed. However, with newer CT machines the amount of radiation is smaller.

Magnetic Resonance Enterography (MRE)
This unique type of MRI can visualize the intestine as well as a CTE test, with one significant advantage: no radiation. The examination is not invasive though it is less readily available. Recent studies point to an additional advantage: MRE usage has been shown to provide not only high quality imaging of the small intestine but also an indication of the disease's activity level at the time of the test, reducing the need for an endoscopic evaluation. This non-invasive evaluation of the degree of tissue inflammation is a true asset in Crohn's disease, when the clinical activity is not always compatible with the severity of intestinal inflammation. Results can help in the decision making process when changes in treatment are being contemplated. MRE can replace both Passage and CTE tests.

Endoscopic Capsule
This test enables imaging of the small intestine, the vast majority of which cannot be visualized through regular gastroscopy or colonoscopy. Patients (10 years or older) are asked to swallow a small capsule that includes a tiny camera, which then transmits three images per second to an external machine which receives the data as the capsule travels through the intestine. With younger patients incapable of swallowing the capsule, it can be placed in the intestine via gastroscopy. When the test is completed, the progression of images can be viewed as a movie on a computer screen, such that inflamed areas suspected as inflicted by IBD can be identified. The test is more accurate than a Passage and the direct view of the intestine's tissue facilitates precise diagnosis of tissue pathologies. Relative to an MRE or a CTE, this exam has several disadvantages: it cannot "see" beyond the inner intestinal lining; the intestine must be prepared in advance for the exam (the precise preparation protocols, including diet restrictions and substances to be taken, differ across medical centers); a rather large capsule must be swallowed; and there is a risk that the capsule could become engaged in areas of the intestine that have become narrow as a complication of the chronic inflammation. In order to reduce this risk, a placebo soluble capsule can be taken prior to the test, and with the use of a detector or simple stomach X-ray the examiner can verify that the capsule has indeed made its way through the entire intestine successfully.
The capsule's diagnostic value is demonstrated in cases in which Crohn's is suspected in the small intestine yet colonoscopy and gastroscopy results are normal. The capsule has further been instrumental in recent years in diagnosing a growing number of cases of active Crohn's disease limited to the middle small intestine, a much less common form of the disease.

This veteran machine continuously undergoes technological upgrading and various "face lifts", constantly improving its resolution. Skilled hands can measure the thickness of the intestine (a finding which could point to an inflammation of the intestine's lining), identify stomach abscesses, free liquid in the stomach and other rare complications. Ultrasound evaluation is an excellent screening test when there are non-specific suspicions and for monitoring acute situations of known cases of Crohn's. The test is simple, inexpensive and does not involve radiation. Its disadvantage is its relatively low level of accuracy compared to the other imaging technologies mentioned, which is further dependent on the examiner's skills. Recently, more advanced methods applying ultrasound technology to IBD have been developed, such as using duplex technology (which measures the blood flow to the intestine, that intensifies during inflammation) and injection of contrast substances.  
Additional Tests
Additional examinations, such as observing white blood cells marked with radioactive markers which tend to concentrate in inflamed areas, exist in the world but are not in routine use in Israel. Additional tests rarely add vital information to the results of the aforementioned baseline tests.