Long term use of questran or the like causes deficiencies in the oil soluble vitamins. This has many resulting problems. See:
http://medical-dictionary.thefreedictionary.com/Questran and look at "Adverse Reactions" under "Metabolic".
Ask your doctor about
getting supplements to replace the lost vitamins A, D, E, and K. Vitamin K may be hard to find without a prescript
ion, especially in Europe.