1. Nishikawa J, et al. Toxicity study with sodium picosulfate in cultured liver cells of rabbit, rat and man. Arzneimittelforschung. 1981;31(2):321-5. 2. Geboes K, et al. Effects of 'contact laxatives' on intestinal and colonic epithelial cell proliferation. Pharmacology. 1993 Oct;47 Suppl 1:187-95. 3. Fioramonti J, et al. In vivo motility of rat colon chronically pretreated with sennosides. Pharmacology. 1993 Oct;47 Suppl 1:155-61. 4. Regev A, et al. Comparison of two bowel preparations for colonoscopy: sodium picosulphate with magnesium citrate versus sulphate-free polyethylene glycol lavage solution. Am J Gastroenterol. 1998 Sep;93(9):1478-82.