Constipation is a common problem in patients and the general population. Hot packs can relieve constipation, but the effect on small-intestinal motility remains unknown. We aimed to determine the effect of hot packs on small-intestinal motility and subjective feelings associated with bowel activity after removing the hot packs. Thirty-four normal adults were assigned to either an experimental group (n = 18) or a control group (n = 16). Hot and normal packs were applied for 10 minutes to the lumbar regions of the experimental and control groups, respectively. Small-intestinal motility was measured by Doppler ultrasound before, during, and after pack application. Subjective feelings were also evaluated after removing the packs. The number of small-intestinal peristalses and subjective feelings of 20 participants showing anechoic areas in the small-intestinal lumen were analyzed.