A 3 to 4-inch, pear-shaped, bluish-green sac hanging from the underside of the liver. The liver cleans the blood of toxins and packages them along with cholesterol, bile salts, lecithin and other substances in a digestive mixture known as bile. The bile first goes to the gull bladder where it is concentrated and stored until food arrives in the duodenum. When food is pushed into the duodenum from the stomach, the bile is excreted from the gull bladder, through the bile duct, into the intestines and eventually exits the body within the feces.

Gallstones
Abnormal concentrations of bile acids, cholesterol and phospholipids can result in the formation of a stone composed of cholesterol or calcium salt. Gallstones sizes vary from a tiny grain of sand, to a pea-sized, to filing the entire gall bladder. Around 20 million Americans have gallstones. 1 in every 10 people has a gallstone without knowing it. If the stone is pushed out of the gall bladder and becomes lodged inside the cystic duct or bile duct, the person does become aware of it, thanks to nausea, vomiting, and/or upper right abdominal pain. Once a gallstone is lodged in the cystic duct or bile duct, an infection of the gallbladder can develop, causing pain in the upper right abdomen, across the chest and/or in the upper abdomen shooting into either shoulder and radiating down the back. Other symptoms include fever, nausea, vomiting, coffee-colored urine, chills and jaundice (yellowing of the skin and of the whites of the eyes). If you experience these symptoms see a physician immediately. An untreated infection of the gallbladder can result in death. Women are twice as likely to develop gallstones as men are. Repeat dieting and rapid changes in weight can increase your risk of gallstones by 70%. Exercise can reduce your risk of gallstones by 40%.

According to the Guiness Book of World Records the largest gall bladder ever recorded was removed from a 69 year old woman. The organ weighed 23 lb., more than 3 times the weight of a newborn baby. The patient fully recovered.

Other Glands involved in digestion
Liver
Pancreas

Digestion

Digestive Organs
Mouth
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
Rectum
Anal canal