Gastrointestinal bleeding

Upper GI bleeding

• Bleeding proximal to the ligament of Treitz presents with haematemesis (fresh or coffee-ground) and/or melaena; a brisk upper bleed can cause fresh rectal bleeding with shock.
• Raised urea with normal creatinine: blood in the gut is digested and its protein absorbed, and the liver turns the amino acids into urea; hypovolaemia adds a prerenal element. In the first hours the urea may still be normal.

• Zollinger–Ellison syndrome: a gastrinoma (duodenum or pancreas, sometimes MEN 1) causes recurrent and atypical ulcers (jejunal, multiple), diarrhoea (acid inactivates lipase and damages mucosa) and a very high gastrin with low gastric pH. A high gastrin with high pH (achlorhydria, PPIs, atrophic gastritis) is a secondary rise, not a tumour.
• Peptic ulcer pain travels in visceral afferents with sympathetic fibres (greater splanchnic nerve, T5–T9), so it is felt in the epigastrium. For pain elsewhere (such as toothache) in an ulcer patient, give paracetamol, not NSAIDs.

Risk scores and endoscopy

• Glasgow–Blatchford score (before endoscopy: urea, Hb, systolic BP, pulse, melaena, syncope, liver disease, heart failure): its main use is to find low-risk patients (score 0) who can be managed as outpatients.
• Rockall score (with endoscopic findings) predicts rebleeding and death.
• Forrest classification: Ia spurting, Ib oozing, IIa visible vessel, IIb adherent clot, IIc pigmented spot, III clean base; Ia–IIb need endoscopic therapy.
• Resuscitation: two large cannulae, crossmatch, fluids, restrictive transfusion (Hb about 70 g/L; 80 with heart disease) unless massive, correct clotting and anticoagulants.
• Endoscopy within 24 hours, immediately after resuscitation if unstable.
• Ulcer bleeding: dual endoscopic therapy (adrenaline plus clips or thermal coagulation); high-dose PPI afterwards; test and treat *H. pylori*; stop NSAIDs. Rebleeding: repeat endoscopy, then embolisation or surgery (under-running the gastroduodenal artery).
• Variceal bleeding: terlipressin (splanchnic vasoconstriction) and prophylactic antibiotics (ceftriaxone) before endoscopy; band ligation for oesophageal varices, cyanoacrylate glue for gastric varices; Sengstaken–Blakemore tube as a temporary bridge to TIPS; avoid over-transfusion; lactulose. Secondary prevention: repeated banding plus a non-selective beta-blocker (propranolol, carvedilol).

Perforated peptic ulcer

• Sudden severe epigastric pain becoming generalised, board-like rigidity, often with NSAID use. The best initial investigation is an erect chest X-ray for free gas under the diaphragm; up to a quarter show none, so CT is used if doubt remains.

Lower GI bleeding

• Meckel diverticulum: a persistent vitelline (vitellointestinal) duct remnant of the midgut; a true diverticulum (all layers) on the antimesenteric border of the ileum, about 60 cm (2 feet) from the ileocaecal valve; in about 2% of people; may contain gastric or pancreatic tissue; can cause bleeding, diverticulitis, intussusception or obstruction.
• Investigation: digital rectal examination and proctoscopy always; stable patients get colonoscopy; active unstable bleeding gets CT angiography (detects 0.5 mL/min), then mesenteric embolisation; an upper GI endoscopy if the bleed is brisk and the urea raised; red cell scan or capsule endoscopy for obscure bleeding.

Haemorrhoids and anal conditions

• The dentate line marks the embryological junction of endoderm and ectoderm. Above it, the mucosa has visceral (autonomic) innervation, which senses only stretch, so internal haemorrhoids are painless. Below it, the anoderm has somatic innervation (inferior rectal branch of the pudendal nerve), so a thrombosed external haemorrhoid or an anal fissure is very painful.
• Internal haemorrhoids are enlarged anal cushions at 3, 7 and 11 o'clock (lithotomy). Grades: I bleed, II prolapse and reduce spontaneously, III need manual reduction, IV irreducible. Fibre and fluids; banding for I–III; haemorrhoidectomy for III–IV.
• Anal fissure: posterior midline tear (anterior after childbirth), sentinel tag; lateral or multiple fissures suggest Crohn disease, TB, HIV, syphilis or cancer. Topical GTN or diltiazem relaxes the internal sphincter; botulinum toxin; lateral internal sphincterotomy for chronic cases.
• Perianal abscess: incision and drainage. Fistula-in-ano: Goodsall rule (external opening anterior to the transverse anal line gives a straight radial track; posterior gives a curved track to the posterior midline); fistulotomy for low, seton for high fistulas; consider Crohn disease.
• Pilonidal sinus: hairy natal cleft in young men; drain abscesses, excise later.

Dysphagia

• Any new dysphagia is a red flag: urgent endoscopy to exclude cancer, especially with weight loss in older people.

• External compression: an enlarged left atrium (mitral stenosis with malar flush) presses on the oesophagus; also goitre, mediastinal nodes, aortic aneurysm, and an aberrant right subclavian artery (dysphagia lusoria).
• Dysphagia with hoarseness: a mediastinal or oesophageal cancer involving the recurrent laryngeal nerve (usually the left, which loops under the aortic arch).
• Achalasia: loss of inhibitory (nitric oxide, VIP) neurons in the myenteric plexus prevents lower sphincter relaxation and abolishes peristalsis; bird's beak on barium; manometry is the gold standard; treat with pneumatic dilatation, Heller cardiomyotomy with fundoplication, POEM or botulinum toxin; it carries a squamous carcinoma risk.
• Pharyngeal pouch (Zenker): elderly, regurgitation of undigested food, halitosis, gurgling neck lump; it herniates through Killian dehiscence between the thyropharyngeus and cricopharyngeus; barium swallow first, because blind endoscopy can perforate it.
• Odynophagia: candida, herpes, CMV (HIV), pill oesophagitis (doxycycline, bisphosphonates, NSAIDs, potassium), caustic injury, cancer.

Remember Above the dentate line pain is absent; behind the duodenum lies the gastroduodenal artery; urea rises because blood is digested.

Exam trap Posterior duodenal ulcers bleed from the gastroduodenal artery; anterior ones perforate (erect chest X-ray first).

Exam trap Dysphagia to solids then liquids is mechanical; to both from the start suggests achalasia.

How FCPS asks about this

• Raised urea in upper GI bleed: digested blood protein absorbed; Blatchford score identifies low-risk outpatients.
• Painless internal haemorrhoids: visceral innervation above the dentate line; fissures hurt because the anoderm is somatic.
• Varices: terlipressin and antibiotics, then banding; left gastric vein anastomosis; beta-blocker for secondary prevention.
• Meckel diverticulum: painless bleeding in a child from ectopic gastric mucosa; midgut vitelline duct remnant 2 feet from the ileocaecal valve.
• Mucus and hypokalaemia: rectal villous adenoma.
• Recurrent jejunal ulcers with diarrhoea: Zollinger–Ellison syndrome, high gastrin with low pH.
• Dysphagia: achalasia diagnosed by manometry; pharyngeal pouch by barium swallow; left atrial enlargement compresses the oesophagus.