Gastrointestinal bleeding is blood loss anywhere from the mouth to the anus. It is grouped into upper (proximal to the ligament of Treitz) and lower (distal to that point) sources, each with characteristic clinical pictures. Blood may be seen, hidden in stool, or detected only by laboratory tests; volume can range from trivial to rapidly fatal. Recognising the varied presentations guides location, pace, urgency of evaluation, and need for resuscitation.
- Visible upper-tract patterns
• Hematemesis: vomiting red or clotted blood indicates brisk bleeding; coffee-ground material signifies slower gastric contact.
• Melena: black, tarry, foul-smelling stool produced by ≥50 mL of upper-tract blood; can persist 2–3 days after bleeding stops.
• Nasogastric aspirate: blood-stained return confirms ongoing upper bleeding; clear bile fluid does not exclude a duodenal source. - Visible lower-tract patterns
• Hematochezia: maroon or bright red blood per rectum, usually implying distal colon or rectum; when massive from an upper source, color may remain red due to rapid transit.
• Melenic streaks mixed with formed stool: suggest right-colon bleeding with adequate transit time for oxidation.
• Occult or intermittent streaks on toilet paper: typical of anorectal sources (haemorrhoids, fissures, proctitis). - Volume-related systemic signs
• Postural dizziness or syncope: ≥15 % circulating volume lost.
• Resting tachycardia >100 beats/min, orthostatic drop >20 mmHg systolic: early hypovolaemia.
• Hypotension <90 mmHg systolic, cold clammy skin, delayed capillary refill: hemorrhagic shock (>30 % loss).
• Thirst, agitation, decreased urine output: compensatory responses preceding measurable pressure fall. - Associated local clues
• Epigastric pain before bleeding: peptic ulcer or erosive gastropathy.
• Severe retching then hematemesis: Mallory-Weiss tear.
• Painless torrential red blood with signs of chronic liver disease: variceal rupture.
• Crampy lower abdominal pain plus bloody diarrhea: colitis (infectious, ischemic, inflammatory).
• Painful passage of bright red blood on surface of otherwise normal stool: anal fissure or prolapsed haemorrhoids. - Red-flag combinations demanding urgent care
Syncope plus any hematemesis, continuous fresh blood via nasogastric tube, hematochezia accompanied by systolic pressure <90 mmHg or heart rate >120 beats/min, and mental confusion with cool extremities.
Summary table
| Presentation | Likely location | Volume implication | Immediate step |
|---|---|---|---|
| Coffee-ground vomitus | Stomach/proximal duodenum | 100–300 mL | Gastroscopy within 24 h |
| Fresh hematemesis + clots | Esophagus/stomach/duodenum | >500 mL often | Large-bore IV, cross-match 4–6 units |
| Melena, stable vitals | Upper GI or right colon | 50–200 mL | Monitor vitals, Hb at 6 h intervals |
| Bright red blood per rectum | Distal colon/rectum OR rapid upper | Variable | Anoscopy + colonoscopy; consider tagged scan if massive |
| Occult blood, no visible change | Any, slow ooze | <50 mL/day | Evaluate for anemia, confirm with fecal immunochemical test |