Yamada E, et al. - Authors planned this study to assess the possible clinical factors associated with the symptoms of constipation in patients with diabetes mellitus (DM). Diabetic neuropathy, defined as peripheral neuropathy of the lower limbs, seemed to have a significant association with symptoms of constipation. For constipation, peripheral neuropathy of the lower limbs was not a direct risk factor but could be a useful criterion when assessing whether constipation is associated with DM.