Digestion Q&A by Dr. Marks
The gallbladder is a muscular, hollow sack, approximately two inches by one inch that attaches to the lower edge of the liver. The purpose of the gallbladder is to store and concentrate bile. After a meal the muscular gallbladder contracts, and the stored bile is secreted into the intestine where it helps digest food, particularly fats.
The term "contracted gallbladder" can refer to two different situations. The first occurs following a meal or after maneuvers that cause the muscle of the gallbladder to contract, for example, ingestion of fat or injection intravenously of the hormone that is responsible for causing the gallbladder to contract. In either case, the gallbladder empties, becomes smaller, and is said to be contracted. This is the normal situation. The second situation is when the gallbladder is diseased, specifically when there has been inflammation, for example, due to gallstones, that has resulted in scarring of the gallbladder. Scarring causes the gallbladder to become smaller, for example, contracted, and the gallbladder no longer functions normally. The "contraction" in the latter situation is clearly different from the "contraction" in the first.
The gallbladder is most frequently evaluated by ultrasonography since fluid-filled sacks like the gallbladder are easily identified by ultrasound waves. If the gallbladder is contracted, no fluid-filled sack, or only a very small one, is seen where the gallbladder should be. This implies that the gallbladder is contracted (rarely is the gallbladder missing from birth); however, as per the previous discussion, it may be contracted because it is diseased (scarred) or because the person having the ultrasonogram has just eaten. That is why ultrasonograms of the gallbladder usually are done fasting, for example, so that an absence of the gallbladder (indicating a contracted gallbladder) means a diseased gallbladder and not a contracted one that is due to eating.
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Last Editorial Review: 2/14/2007