Sensory testing of the human gastrointestinal tract

Figure 2 Illustration of mechanical stimulation in the esophagus. The bag was filled at an infusion speed of 25 mL/min. During distension, (A) pressure, (B) cross-sectional area (CSA) and (C) pain intensity was recorded on line. The increase in CSA corresponded with increasing stimulus intensity after the bag was filled with water, whereas there was little relation between the pressure waves and the sensation. The pain intensity was rated on a visual analogue scale (VAS), with 5 as the pain threshold. An intensity of 8 on the VAS resulted in reversal of the pump. For details see Drewes et al[35].