A spectroscopic investigation of the formation mechanism of pigment gallstones

Further spectroscopic studies of gallstones are reviewed with an emphasis on the formation of black pigment gallstones. This type of gallstone appears mainly in Western countries, with only 3% of the cholelithiasis patients in China having black gallstones. Fourier transform infrared absorption and electron paramagnetic resonance are used as spectroscopic probes of gallstones and their metal bilirubinate components. Nonlinear phenomena in gallstone formation were investigated through the appearance of ring structure in gallstones and fractal patterns in the formation in the precipitates of bile salt systems. Although a complete understanding of gallstone formation has not yet been achieved, interesting progress toward this goal has been made recently.