HTR4 and Chronic constipation: In the attempt to mitigate intestinal damage in this line, we tested the efficacy of the 5-HT4R agonist velusetrag, a highly selective compound developed to treat chronic constipation and found to be effective in humans and rodents (Golberg et al., 2010; Long et al., 2012; Kuo et al., 2021; Abell et al., 2023).