Sepsis is a host extreme immune response to infection, leading to tissue and organ injury, which can be life threatening. When sepsis is severe, it can also cause diarrhea, nausea, or vomiting. Such gastrointestinal symptoms may be associated with excessive production of 5-hydroxytriptamine (5-HT). 5-HT is synthesized from tryptophan hydroxylase (TPH), a rate-limiting enzyme, in enterochromaffin cells, primarily in the intestinal mucosa, and catabolized into 5-hydroxyindole acetic acid (5-HIAA) by monoamine oxidase (MAO). In this study, we investigated the longitudinal change in intestinal 5-HT synthesis and metabolism in mice with cecal ligation and puncture (CLP)-induced sepsis. Three, 6, 12, 24 and 48 h after sepsis induction by CLP, jejunal tissues were dissected. Compared to sham-operated mice, jejunal 5-HT content was slightly but significantly increased at 24 h. The 5-HIAA content was significantly increased at 3, 6 and 24 h in CLP mice. TPH1 mRNA expression was transiently elevated in CLP mice with a peak at 12 h. MAO-A mRNA expression was elevated at 6 h but significantly declined at 12 and 24 h in CLP mice. These results demonstrate that the 5-HT metabolism can be enhanced in jejunal tissue prior to 5-HT synthesis, which may provide a basic insight into the understanding of the pathological role of 5-HT in sepsis.