The patients with mesenteritis cicatricans were investigated before and after the operation myographically in their dorsal muscles at rest. These discharges were seen in 18 of 20 cases with lumbago. and in 4 of 15 cases without it. After the resection of scar or Rankin-Reamonth's operation, there was seen disappearance or decrease of discharges, which corresponded with disapperance of lumbago and the objective findings. From the fact, that countless nerve fibres in the scar of the mesenterium were found by Bielschowsky's sheath staining and that no discharge was seen in those without mesenteric scar, it was concluded that the lumbago in this disease was to be a viscerosensory reflex caused by abnormal stimulation of afferent nerves, which passed through the scar.