Why black stools with collapse matters
Black, tarry stools mean bleeding high in the gut, and a faint means a lot of blood has been lost. Shock can look quiet in someone lying flat, so recognise it and start resuscitation before working out what started the bleeding.
What to ask in the history
- How long the stools have been black, and how often
- Vomiting: fresh blood or coffee grounds
- The faint: what he was doing, warning signs, how quickly he came round
- Dizziness on standing, breathlessness, chest pain
- Painkillers: which ones, from where, how many, for how long
- Aspirin, blood thinners, steroids, alcohol
- Indigestion, previous ulcers
- Iron tablets or bismuth, which turn stools black without blood
Red flags
- Fainting, or dizziness on sitting up
- Fast pulse, low blood pressure, cold clammy skin
- Chest pain or breathlessness
- Ongoing bleeding
- Older age, heart or kidney disease
- Confusion
What to examine
- Airway, breathing, circulation
- Pulse and blood pressure; a postural drop only if it is safe to check
- Pallor, capillary refill
- Abdomen: tenderness, guarding, rigidity
- Rectal examination to confirm black stool
- Signs of liver disease
First investigations
- Full blood count, crossmatch, clotting
- Urea and creatinine, liver function
- ECG, since a heart short of blood can be strained
- Lactate
- A pre-endoscopy risk score
- Upper GI endoscopy
- Erect chest X-ray or CT if perforation is suspected
Differential diagnosis of black stools with collapse
Grouped, not ranked. Which one fits this patient is for you to work out in the case.
Ulcer disease
- Gastric or duodenal ulcer
- Erosive gastritis
Other upper GI causes
- Varices
- Oesophagitis
- Mallory-Weiss tear
- Cancer
- Vascular lesions
Not blood
- Iron or bismuth
- Some foods
Lower down
- A brisk bleed from the small or large bowel
Common mistakes
- Putting the faint down to a simple faint.
- Reading a high urea as kidney failure, when digested blood in the gut also raises it.
- Missing a perforation in someone with ulcer risk factors.
- Not asking specifically about painkillers bought without a prescription.