Colestipol is a bile acid sequestrant

Bile acid sequestrant

The bile acid sequestrants are a group of medications used to bind certain components of bile in the gastrointestinal tract. They disrupt the enterohepatic circulation of bile acids by sequestering them and preventing their reabsorption from the gut. In general, they are classified as hypolipidemic...

.
It works in the gut trapping bile salts, and preventing them from being reabsorbed.

This leads to
decreased enterohepatic recirculation

Enterohepatic circulation

Enterohepatic circulation refers to the circulation of biliary acids from the liver, where they are produced and secreted in the bile, to the small intestine, where it aids in digestion of fats and other substances, back to the liver....

 of bile salts,
increased synthesis of new bile salts by the liver,
decreased liver cholesterol

Cholesterol

Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...

,
increased LDL receptor expression,
and
decreasing LDL in blood.

Side effects

• Increases in VLDL and TAG
  Triglyceride
  A triglyceride is an ester derived from glycerol and three fatty acids. There are many triglycerides, depending on the oil source, some are highly unsaturated, some less so....
  
   synthesis
• Gastrointestinal tract disturbances
• Malabsorption
  Malabsorption
  Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal tract.Impairment can be of single or multiple nutrients depending on the abnormality...
  
   of lipid soluble vitamins (A,D,E,K) and lipid soluble drugs

Contrandications

Colestipol is contraindicated in hypotriglyceridemia.