The bile helps your body break down and absorb the fat you eat.
When you eat fat, your liver sends bile directly into the duodenum (small intestine). Your gallbladder will also spring into action, contracting and squeezing more concentrated bile through the common bile duct into the small intestine to aid in the breakdown of the fat. Carbs and proteins are more easily digested and don't need this extra bile.
Bile is made up of water, cholesterol, lecithin, bile salts (which break fats into smaller droplets that are easier for digestive enzymes to process) and bile pigments. The primary bile pigment is bilirubin, made from red blood cells that are broken down in the liver. This pigment is responsible for making urine yellow and stool brown.
Your pancreas also plays an important role in the digestive process. It produces and sends enzymes into the common bile duct via the pancreatic duct. Together, the digestive juices from your liver and pancreatic enzymes break down the food you eat into liquid form so that your body can absorb the nutrients from it.