To facilitate the method of obtaining rectal or sigmoidal contents in patients suffering with intestinal disorders, a sigmoid aspirator has been devised. The instrument is 8 inches long and three-fourths inch in diameter. It is composed of a barrel and an obturator. Both present four openings, each one-sixteenth inch diameter about one inch from the distal end. These openings correspond with each other when the obturator is inserted into the barrel. The obturator consists of a hollow tube, the distal end of which is enlarged in order to fit accurately into the distal end of the barrel. The proximal end of the obturator presents a lock mechanism and also a well ground tip, which is made to fit an ordinary Luer syringe. The openings in the barrel may be opened or closed by rotating the obturator at R. Figure 1 shows the barrel. Figure 2 shows the obturator with lock