Healthy Colon

The last post was on the rectum so I thought I would work my way backward through the digestive system. The colon or large intestine is the last part of the digestive system and is composed of 4 parts: Ascending colon, Transverse colon, Descending colon, Sigmoid colon.

The colon has 3 major functions. First, it reabsorbs a large amount of water that was used in the digestive process. If food moves too quickly through the colon (irritable bowel, viral infection, etc) the water does not get reabsorbed and the result is watery stool (diarrhea).

The second major function is fat soluble vitamin absorption. In particular, vitamin K is one of the vitamins absorbed by the colon. Vitamin K is obtained through the consumption of leafy green vegetables (spinach, kale, cabbage, broccoli, cauliflower, avocado, kiwi) and from the bacterial flora in the colon that produces the vitamin. Vitamin K is absorbed by the colon and then is used in the liver to produce coagulation factors. If you get cut, a cascade of coagulation factors work to stop the bleeding. If you are deficient in vitamin K you will not produce coagulation factors and you will not stop bleeding. Babies receive a vitamin K shot at birth because they do not have intestinal flora yet and can be deficient in vitamin K and at risk for bleeding. An interesting side note: warfarin (coumadin) a blood thinner (originally a rat poison) "thins" the blood by blocking vitamin K from producing coagulation factors.

The third major function of the colon is to provide a home for bacteria that serve a symbiotic with their host. First, bacteria produce vitamin K as previously discussed. We eat several foods that contain fiber. Our digestive systems cannot digest many forms of fiber but bacteria can. The bacteria feeds off the fiber and in turn produce acetate, propionate, and butyrate which is used by the colon lining for nourishment (can you say kreb cycle?).

So how do we maintain a healthy colon? Most problems in the colon can be resolved by eating a diet high in fiber and fruit and low in meats and carbohydrates. Fiber keeps the bacteria happy as well as the colon lining. It prevents constipation by preventing reabsorption of all the water. It prevents diarrhea by bulking up the stool.

The most common pathologies of the colon are as follows:

Diverticulosis/Diverticulitis: Diets rich in processed carbohydrates and low in fiber result in increased pressures within the colon. This pressure results in small out-pouchings within the lining of the colon wall. These out-pouching can get infected and bleed. It was previously thought that seeds, nuts, and popcorn blocked the openings of these pouches but this has been disproven. The best way to avoid this condition is to avoid diets high in carbohydrates and eat more fiber!

Clostridium Difficile colitis: This can be a life-threatening infection of the colon. It is usually caused by an antibiotic killing off your normal flora allowing a bad bug to take up residence. This organism can be very resistant to antibiotics and difficult to treat. This can be prevented by avoiding frivolous use of antibiotics, good hand washing, and keeping a healthy bowel. There is some evidence that probiotics while taking an antibiotic may help. Some hospitals are worse than others when it comes to transmitting this bug between patients so it wouldn't hurt to know how good your hospital is at preventing these types of infections.

Colon Cancer: There is no reason in this day and age for someone to have colon cancer, let alone die from it. Colon cancer usually starts as a polyp that grows slowly over time into a cancer. If you catch and remove the polyps early you should not get colon cancer. It is recommend that everyone have a colonoscopy at age 50, sooner if you have a family history. A full colonoscopy that is free of polyps will buy you 10 years peace of mind before you need another one.

Irritable Bowel Syndrome: We do not completely understand irritable bowel syndrome. It is recommended generally that you eat fiber and maintain a healthy bowel to prevent problems. Remember fiber helps to prevent constipation and diarrhea. Anxiety and stress can also affect the colon and speed the transit, resulting in diarrhea. Relaxation techniques and reducing stress are important to maintaining a healthy colon and happy stools.

Remember, fiber is your friend. I do not think you can eat too much of it. And it wont make you fat because you can't digest it. Now only if we can make it taste like krispy kremes;)