Blood is discharged from the anus, and the stool is bright red, dark red or tarry (black stool), which is called bloody stool.
Bloody stool is just a symptom, not a disease. Bloody stool is more common in lower gastrointestinal bleeding, especially in colon and rectum diseases, but it can also be seen in upper gastrointestinal bleeding. The color of blood in stool depends on the location of gastrointestinal bleeding, the amount of bleeding and the time that blood stays in gastrointestinal tract. Bloody stool is accompanied by bleeding of skin, mucosa or other organs, which is more common in hematological diseases and other systemic diseases, such as leukemia and disseminated intravascular coagulation.
Etiology:
1. Diseases of digestive tract itself, such as esophageal/gastric varices bleeding, gastric ulcer and intestinal ulcer and inflammation, parasitic infection, tumor (including polyp and cancer), hemorrhoids, intussusception, anal fissure, dry stool, etc.
2. Diseases of other systems outside the digestive tract, such as hematological diseases, acute infectious diseases, vitamin deficiency, poisoning or toxic effects of drugs.
3. Children's bloody stools are mostly caused by intestinal polyps. Blood is bright red and painless, and blood is not mixed; It can also be seen in bacillary dysentery, intussusception and blood system diseases. Adult hematochezia is mostly caused by hemorrhoids, anal fistula, anal fissure, intestinal polyp, intestinal cancer and inflammatory bowel disease.