The goal of this research is to compare alterations of gut microbiota and fecal metabolomics alterations between inflammatory bowel disease patients infected with or without Clostridioides difficile. The main questions it aim to answer are: which bacterial genus or fecal metabolites can discriminate IBD patients infected or more likely to be infected with Clostridioides difficile and their role in the pathogenesis of Clostridioides difficile. type of study: observational study participant population/health conditions 1. population diagnosed with Ulcerative colitis or Crohn's disease 2. Having diarrhea Participants will be included in this research. If there is a comparison group: Researchers will compare healthy people without IBD or any diarrhea to see if disease or diarrhea would affect the gut microbiota and metabolites.