How does the examination work?
The examination method according to Sellink is also known as enteroclysma or double contrast examination of the small intestine according to Sellink. It is used to visualize the small intestine and thus to detect various intestinal diseases. The patient must be fasting and have taken laxatives beforehand, otherwise the bowel cannot be evaluated.
The patient is administered two different contrast media during the examination. A positive contrast medium (barium sulfate) and a negative contrast medium (methyl cellulose). Positive means that the contrast agent leads to an increase in the signal in the imaging, i.e. the areas to which the contrast agent is attached appear brighter.
In this case these are the intestinal walls. The negative contrast medium, on the other hand, leads to a weakening of the signal intensity. One obtains a double contrast.
First, a probe is inserted through the patient’s nose, through which the positive contrast medium is first administered. This is followed by the negative contrast medium, which ensures that the positive contrast medium is distributed throughout the intestine and attaches itself to the intestinal walls. The negative contrast medium with the weaker signal intensity is then located in the middle of the intestine, so that the intestinal walls shine brighter than the lumen.
This ensures that the intestinal walls can be assessed particularly well on the X-rays taken of the patient. The physician pays attention to the folding and thickness of the intestinal walls, leaks, i.e. whether the contrast medium is leaking at a certain point, disturbances of the intestinal motor function, constrictions (stenoses) of the intestine as well as filling defects, i.e. places where no contrast medium accumulates. The small intestine can therefore be examined very well for abnormalities during the examination.
Indications for the Sellink examination
There are various indications for which the Sellink examination method is used. These include chronic inflammatory bowel diseases (Crohn’s disease, ulcerative colitis), disorders of bowel motor function, the detection of intestinal tumors, diverticula, as well as abscesses, fistulas and narrowings (stenoses). There are, however, circumstances in which the Sellink examination method may not be used.
These include suspected leakage in the intestinal walls (perforation), as otherwise the contrast medium would leak into the free abdominal cavity. In the case of barium sulfate, this would lead to serious complications with inflammation of the peritoneum, which is difficult to treat and dangerous for the patient. In addition, the Sellink examination method must not be used if the patient has undergone abdominal surgery in the last 14 days, if paralysis of the bowel (paralysis) or intestinal obstruction (ileus) is suspected.
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