Diarrhea combined with certain conditions may be a sign of a serious condition, commonly combined with blood in the stool, anemia, weight loss, abdominal pain, and abdominal masses. 1. Combined with blood in stool or anemia: diarrhea combined with blood in stool suggests the presence of gastrointestinal bleeding, especially chronic gastrointestinal bleeding combined with anemia often suggests colorectal cancer, ulcerative colitis, Crohn’s disease and other gastrointestinal diseases. In this case, it is recommended to seek timely medical treatment to avoid further aggravation and progression of the disease. 2. Weight loss: chronic diarrhea with progressive weight loss should be suspected of intestinal malignant tumors, especially in middle-aged people over 40 years old or people with family history of intestinal malignant tumors should be more alert. 3. Abdominal pain: long-term chronic diarrhea with chronic diarrhea can be seen in irritable bowel syndrome, chronic intestinal infections, inflammatory bowel disease, colorectal cancer, etc.; diarrhea with acute severe abdominal pain may be acute hemorrhagic necrotizing enterocolitis, superior mesenteric artery embolism and other diseases. 4. Abdominal mass: long-term chronic diarrhea with abdominal mass formation may be caused by intestinal tuberculosis, Crohn’s disease, colorectal cancer and so on. In addition to the above signs, diarrhea accompanied by subcutaneous bleeding, ascites formation, jaundice and other factors should also be vigilant, and it is recommended that the patient go to the hospital as soon as possible to find out the cause of the timely treatment.