1.   A small specimen of tissue can be taken for examination through a biopsy channel.

2.   Test agents were infused through the biopsy channel of the colonoscope.

3.   The flexible Doppler probe was passed down the biopsy channel of the endoscope and was positioned under direct vision over the lesion.

4.   The flowmeter probe was passed through the biopsy channel of the endoscope and the tip was placed in gentle contact with the mucosa.