õõneselundite siseseinte uurimine toruja endoskoobi abil, milles on valgusjuhe ja valgusti, (a procedure that) involves passing an optical instrument along either natural body pathways such as the digestive tract, or through keyhole incisions to examine the interior parts of the body, study of the interior of hollow organs, such as the intestines and the reproductive organs, using a flexible probe, which contains optical fibres for transmitting images onto a screen