Under normal circumstances, human intestinal fluid is pale yellow in color. Because intestinal fluid is a tissue fluid secreted by epithelial cells in the intestinal organ tissues, it appears as a clear, viscous liquid itself. However, the bile stored in the pancreatic, gallbladder, duodenum and other digestive organs is metabolized outside the body through the intestinal tissues, so the intestinal fluid is mixed with bile. Bile is a golden-yellow liquid, so it causes the intestinal fluid to appear yellowish. In addition, intestinal fluid also contains a variety of digestive enzymes such as trypsinogen, aminopeptidase, and lactase, which help intestinal tissues break down and absorb nutrients from food. If the intestinal fluid has other abnormal colors, it is mostly considered to be the adverse symptoms caused by digestive system diseases, such as intestinal flora disorders, segmental ileitis, gastrointestinal neurosis, etc.