Medications used in binding bile components in gastrointestinal tract are known as bile acid sequestrants. The bile acid sequestrants such as colesevelam (Welchol), colestipol (Colestid) and cholestyramine (Questran) help in lowering LDL cholesterol levels in the body. The drugs mentioned above, belong to a group called synthetic polymeric resins. The secretion of bile acid through stools increases due to these sequestrants. This process prevents the bile acids from returning to the liver. The liver is forced to increase the production of bile acids; it converts cholesterol into acids and thereby, levels of blood cholesterol are lowered.

Bile Acid Sequestrants
Cholesterol, a fatty substance present in the body is harmful for the health of heart. Excess deposition of cholesterol results in the blockage of arteries. It increases the risk of heart attacks and strokes. One should thus, undertake measures to reduce the levels of cholesterol in the body. Bile acid sequestrants are among the various means used to control the cholesterol levels in the body. The working of these is quite simple to understand. They are basically, polymer compounds. The sequestrants act as ion exchange resins when used in treatments. The bile acids are bound by these sequestrants through the exchange of anions (for example, choride ions). These sequestrants being polymers in their fundamental structure, are not absorbed in the bloodstream through guts. Therefore, their excretion takes place through the gastrointestinal tract by means of feces.

Apart from using them for lowering the LDL cholesterol, bile acid sequestrants can also be employed for the treatment of diarrhea and pruritus.

When bile salts enter the colon and do not get absorbed in the small intestine, the resulting condition is diarrhea. The bile acid sequestrants can be used in such cases for the treatment of diarrhea. The diarrhea of this kind is a possible side-effect of the removal of gallbladder.

It is a kind of itching experienced when bile acids deposit in the skin. Such a condition might occur in people who suffer from liver problems like cirrhosis. The bile acid sequestrants can also be used to prevent pruritus.

Side Effects
The bile acid sequestrants though are beneficial for health, they may also cause some side-effects. They cause discomfort to the gastrointestinal tract and lead to constipation. The problems similar to constipation such as flatulence and dyspepsia are also caused by bile acid sequestrants. Their taste is gritty and few people discontinue the treatment just because of the intolerable taste. It is advisable to add fruit juices to these sequestrants in order to subside the bad taste. Since, the sequestrants don't get absorbed in the blood stream, their usage in treatments doesn't cause any major side effect.

The bile acid sequestrants need to be used carefully, since, they prevent some vitamins and drugs from getting absorbed in the body. Therefore, the vitamin proves to be of no use to the body. People suffering from gastrointestinal dysfunction and hemorrhoids are not allowed to consume bile sequestrants. If there is any kind of problem in the functioning of the intestinal tract after a surgery or due to gastrointestinal dysfunction, these sequestrants may add to the problem, causing fecal impaction. The hemorrhoids may also become worse due to the intake of sequestrants.

The bile acid sequestrants are amongst the important medications used for lowering LDL cholesterols. However, one should take the necessary care and consider the pros and cons of using them.