Portal Hypertensive Colopathy

Abnormal colonic mucosal and vascular changes in patients with portal hypertension, including erythema, vascular ectasia, petechiae, friability, and colonic varices, caused by congestion and venous dilatation of the colonic wall.

• Found in about 30 to 70% of patients with cirrhosis on colonoscopy, more often with advanced disease and in the right colon; many are asymptomatic.
• Bleeding is uncommon but accounts for about 3 to 8% of lower gastrointestinal bleeding in portal hypertension; chronic occult loss causes iron deficiency anaemia in a sizable minority.
• Causes: cirrhosis (alcohol, hepatitis B and C, steatotic liver disease), schistosomiasis, extrahepatic portal vein obstruction, Budd-Chiari syndrome, and non-cirrhotic portal hypertension.
• Mechanism: raised mesenteric venous pressure, with mucosal venous congestion, capillary dilatation and ectasia, increased nitric oxide and thin-walled vessels.

Usually silent, or an incidental finding; occult bleeding with iron deficiency anaemia, melaena or haematochezia (bright or maroon blood), fatigue.

• Features of portal hypertension: ascites, splenomegaly, jaundice, caput medusae, previous variceal bleeding.
• Differential diagnosis: angiodysplasia, colitis (ischaemic, infective, inflammatory bowel disease), diverticular bleeding, colorectal cancer or polyps, NSAID injury, rectal varices, radiation proctitis, haemorrhoids.
• Complications: iron deficiency anaemia, lower gastrointestinal bleeding with shock (rare), and precipitation of encephalopathy by bleeding.

Colonoscopy (after bowel preparation, with care in decompensated cirrhosis) shows diffuse erythema, cherry-red spots, spider-like or angiodysplasia-like vascular ectasia, friable mucosa, and sometimes colonic varices (blue submucosal veins); typically in the right colon but any segment.

• Histology (if biopsied): dilated, thickened capillaries and veins in the mucosa and submucosa, with oedema and no inflammation; biopsy of lesions for other diagnoses only when needed.
• Exclude other causes: full blood count, ferritin, faecal calprotectin and stool tests for infection, CT abdomen, and colonoscopy for polyps or tumour; capsule endoscopy for small bowel lesions.
• Blood tests for liver status: INR, albumin, bilirubin, creatinine, platelets; hepatitis serology; schistosomiasis tests.
• Upper endoscopy for oesophageal and gastric varices and portal hypertensive gastropathy.

Correct anaemia, treat portal hypertension and the liver disease, and use endoscopic or radiological treatment for bleeding.

• Iron replacement: ferrous sulfate 200 mg once daily or on alternate days for 3 to 6 months, or ferric carboxymaltose 1000 mg IV once (maximum 20 mg/kg) when oral iron is not tolerated or fails; transfuse only for haemoglobin under 70 g/L or symptoms.
• Reduce portal pressure: carvedilol 6.25 mg once daily increasing to 6.25 mg twice daily, or propranolol 20 to 40 mg twice daily titrated to heart rate 55 to 60 beats/min (maximum 160 mg daily without ascites, 80 mg with ascites); stop in refractory ascites with systolic pressure under 90 mmHg (evidence for colopathy bleeding is limited).
• Acute bleeding:
  • Resuscitation, restrictive transfusion (haemoglobin 70 to 80 g/L), correction of severe coagulopathy, high-dependency care.
  • Terlipressin 2 mg IV every 4 hours for 48 hours then 1 mg every 4 hours, or octreotide 50 micrograms IV bolus then 50 micrograms/hour for 2 to 5 days; ceftriaxone 1 g IV daily for up to 7 days; lactulose 30 mL every 8 hours.
  • Endoscopic haemostasis for a focal bleeding site: argon plasma coagulation (30 to 40 watts, 0.8 to 1 L/min), haemoclips, or band ligation for colonic varices.
  • Refractory bleeding: transjugular intrahepatic portosystemic shunt, embolisation, or liver transplantation.
• Treat the cause: alcohol abstinence, hepatitis B (tenofovir 245 mg daily or entecavir 0.5 mg daily), hepatitis C (sofosbuvir-velpatasvir 400/100 mg daily for 12 weeks), weight loss in steatotic disease, schistosomiasis (praziquantel 40 mg/kg once), portal vein thrombosis (anticoagulation).
• Avoid NSAIDs, aspirin and anticoagulants unless essential; avoid constipation and straining (lactulose 15 to 30 mL daily).
• Special groups: children (extrahepatic portal vein obstruction; iron replacement 3 to 6 mg/kg/day of elemental iron, propranolol 1 mg/kg/day, shunt surgery); pregnancy (iron, octreotide for bleeding, avoid terlipressin; plan delivery with hepatology and obstetric teams); elderly (screen for cancer and angiodysplasia); renal impairment (avoid NSAIDs and aminoglycosides, adjust IV iron); anticoagulated patients (review the indication).
• Red flags: haematochezia or melaena with shock, haemoglobin fall of 20 g/L or more, jaundice, ascites with fever, encephalopathy, new weight loss.
• Follow-up: haemoglobin and ferritin at 4 to 8 weeks and every 3 months; colonoscopy for recurrent bleeding or new symptoms and at the age for cancer screening; endoscopic surveillance for varices as scheduled; liver ultrasound every 6 months.