Question

Main symptoms: bleeding in the stool, abdominal pain, diarrhea. Onset time: 5 a.m. this morning. Laboratory test results: positive for occult blood in the stool.

Answer

Hematochezia is typically associated with gastrointestinal diseases. Blood in the stool can result from bleeding in the digestive tract that is passed through the bowel. The color of the blood can range from bright red to dark red or black. The color of the blood in the stool depends on the location of the bleeding, the amount of blood, and how long the blood stays in the digestive tract. Bleeding from the lower gastrointestinal tract (small intestine, colon, rectum, anus) often results in bright red or dark red stools; bleeding from the upper gastrointestinal tract (esophagus, stomach, duodenum) usually results in black stools resembling tar. Common causes include:

  1. Bright red stools: usually from the lower end of the ileum, colon, rectum, or anus. The color of the stool is bright red or dark red and may contain mucus and pus. Common conditions include hemorrhoids and anal fissures. Hemorrhoid bleeding is jet-like when defecating or drips after defecation; anal fissure bleeding is less volume but more severe anal pain. Rectal polyp bleeding may not be much, with blood on the surface of the stool, sometimes the stool becomes narrow and shaped like a strip or has pressure marks. Dysentery has bloody pus stools, frequent bowel movements, and left lower abdominal pain.
  2. Black stools (melena): bleeding from the upper gastrointestinal tract that has not been vomited up.