Abstract: A measuring member and a device to be used for determining the blood flow of the gastrointestinal tract, includes an intestinal probe, having its distal end provided with a flexible inflatable body and at least one pressure sensor mounted on this supporting body. After bringing the inflatable flexible body to predetermined pressure, the pressure sensor will abut the intestinal wall and the measured pressure development, which represents a measure for the blood flow of the gastrointestinal tract, is transformed into a graphical image with the help of the device and/or is transformed into actual values for the blood flow of the gastrointestinal tract. Further, the measuring member measures the development of the pressure within the inflatable flexible body, which represents a measure for the intestinal peristalsis.