Once nutrients are absorbed by the intestine, they pass into the blood stream and are carried to the liver.
The liver has the job of processing all the nutrients, vitamins and other things we ingest and absorb each day
The Liver will turn protein, sugar, and fat into energy which, with the help of pancreatic hormones like insulin, will feed the cells of our body.
During a meal, the gallbladder contracts, sending bile to the small intestine. Once the nutrients have been absorbed and the leftover liquid has passed through the small intestine, what is left of the food you ate is handed over to the large intestine, or colon.
A stool is stored in the sigmoid colon until a "mass movement" empties it into the rectum once or twice a day. When the descending colon becomes full of stool, or feces, it empties its contents into the rectum to begin the process of elimination.
The anus is the last part of the digestive system. The anal sphincters provide fine control of stool. The internal sphincter keeps us from going to the bathroom when we are asleep, or otherwise unaware of the presence of stool. When we get an urge to go to the bathroom, we rely on our external sphincter to keep the stool in until we can get to the toilet. The food you started with, ends up in the toilet and the cycle repeats every time you eat something new.
The Rectum is the sencond last part of the digestive system. The brain then decides if the rectal contents can be released or not. If they can, the sphincters (muscles) relax and the rectum contracts, expelling its contents. If the contents cannot be expelled, the sphincters contract and the rectum accommodates, so that the sensation temporarily goes away.