[narutouzumaki]

These are almost lateral approaches and very different from each other though, with MRI being more like a sonar scan and colonoscopies more like sending a submarine equipped with a camera into the depths.

Both can be very useful and helpful in aiding diagnosis with more data points.

Case in point, I have had an MRI (which showed nothing), several CT scans (which showed temporary blockage) and both methods have not really led to a conclusive diagnosis.