Transit-Pellets® Radiopaque Markers
- FDA 510(k) Class II clearance for US-market
- Device is fully CE marked
- Encapsulated pre-cut radiopaque markers packed for single patient use
- Capsules purely vegetarian
- Easy to administer
- Manufactured in Sweden
A colonic transit study with radiopaque markers is known by a few names – Colon Transit-Pellets test, colonic transit study, colon transit markers study, radiopaque markers test, Sitz marker study, or a radio-opaque markers test.
The Transit-Pellets is a medical device and are intended to be used to assess Colonic Transit Time (CTT) in adult patients with chronic constipation, chronic diarrhea, or troublesome IBS. The markers represent the passage of solid and semi-solid contents. The markers are visible during X-ray due to the properties of Barium Sulphate, which is one of the components of the device.
The most common reason to do this investigation is suspicion of so-called slow-transit constipation. However, with the modification of marker intake on the sixth day, it is also possible to easily measure rapid passage, which could be of interest in the investigation of patients with chronic diarrhea.
Illustration (Source: Medifactia) of the movement of the medical device Transit-Pellets through the colon.
Principles of Operation
The device is prescribed by a physician for the patient to administer the device at home. The device is taken in a transparent Hydroxypropyl-methylcellulose (HPMC) capsule (size -00) and passes through the mouth, throat and gastrointestinal tract. It is not surgically invasive.
On day seven, the patient undergoes an X-ray examination or fluoroscopy in a clinic.
Based on the number of retained markers and their position a Colonic Transit Time (CTT) is calculated and compared to reference values.
Times specified above are examples only.
The radiology examination should be scheduled 12 hours after the evening dose day six.
Why tube-formed markers on day six?
- Can verify that the markers were taken as prescribed
- Can provide important information in case of rapid transit
- If slow transit is present, the day six markers are found in the cecum-ascending colon and thus facilitate the delimitation of cecum
- Can confirm slow passage in the proximal colon, e.g., colonic inertia
Barium
Sulphate
Transit-Pellets Radiopaque Markers – Why 22% Barium Sulphate (BaSO4)?
The composition of the Transit-Pellet markers has been selected to follow advice from international experts so that the markers reflect the transit of the solid and semisolid contents in the colon. Therefore, the proportion of the heavy barium sulphate was selected to be in the range 20-25% so that the specific gravity (SG) of the markers should be well below 2.0. Otherwise, the markers will not yield the actual colonic transit time. If the other standard component silicone or a similar is used in the manufacture process and the proportion of barium is increased to up to around 40% the SG of the particles of will be in the range 2.4 – 2.5! This is far above what is recommended by international experts (see articles by pioneers in the field, e.g. by Dr Cummings, Gut 1976;17:210-18). The radiological visibility will of course increase when using so much barium in the markers but the results obtained will not correctly measure the transit of colonic contents, that have a SG in the range 1.2 – 1.7. The dominating food residue cellulose has about 1.5.
