Pigment Gallstones: Black vs Brown Stones, Causes & Treatment

Pigment gallstones (20% of gallstones) are composed of bilirubin. Black pigment stones: calcium bilirubinate polymer, jet black, hard, small, multiple, exclusively in gallbladder, sterile. Causes: haemolytic anaemia (sickle cell, thalassaemia, hereditary spherocytosis), liver cirrhosis, ileal disease, TPN, age. Brown pigment stones: calcium bilirubinate with cholesterol, brown, soft, crumble easily, can form in gallbladder AND bile ducts (primary CBD stones). Causes: biliary infection (E. coli enzymes deconjugate bilirubin), biliary stasis, strictures, parasites (Ascaris, Clonorchis), recurrent pyogenic cholangitis. Diagnosis: ultrasound detects stones; MRCP assesses bile ducts; blood tests may show haemolysis. Treatment: black stones — laparoscopic cholecystectomy (often recommended even for asymptomatic stones in haemolytic patients); brown CBD stones — ERCP + stone extraction + laparoscopic cholecystectomy; recurrent CBD stones from strictures may need surgical biliary reconstruction.