The human digestive system is a complex network that works tirelessly to convert the food we eat into nutrients and energy that the body needs. But what happens to the food that our bodies can’t digest? Let’s take a closer look at the journey of undigested food in the large intestine.
The Basics
The large intestine, which directly follows the small intestine, is about 5 feet long. Like the small intestine, it’s split into three sections – the cecum, the colon, and the rectum. The colon, which is the largest section, is responsible for most of the work of the large intestine.
The Cecum
Your small intestine allows about 3 cups of unabsorbed residue to travel into the cecum each day. The residue enters the large intestine through the ileocecal sphincter, which allows material to pass into the cecum but prevents the backflow of fecal matter into the small intestine. At this point, the residue contains undigested food – or fiber, water, and some vitamins, minerals, and salts.
The Colon
Once the undigested residue enters the colon, it mixes with mucus and bacteria that live in the large intestine and begins the formation of fecal matter. As the fecal matter moves through the colon, the colon absorbs most of the water and some of the remaining vitamins and minerals. The bacteria that live in your colon use the material to produce some vitamins, like B vitamins, biotin, and vitamin K. The bacteria also turn some of the unabsorbed carbohydrates into methane gas, carbon dioxide, and hydrogen. The remaining matter is propelled toward the rectum, the final portion of the large intestine.
The Rectum
When fecal matter reaches the rectum, the final 8-inch section of the large intestine, it triggers the defecation reflex – the signal that lets you know you have to go to the bathroom. At this point, you either eliminate the fecal matter through the anus or it remains stored in the rectum until you do.
Conclusion
The large intestine plays a crucial role in the digestion process, handling the undigested food and turning it into waste for removal from the body. It’s a complex process that involves various stages and components, all working together to ensure the body functions properly. So, the next time you think about digestion, remember the important role your large intestine plays!