Studies attempting to link infrequent defecation and colon cancer have been inconclusive thus far. Some have shown a significant risk in colorectal cancers in those with frequent or prolonged constipation, while others have indicated that those who defecate most often may be at an increased risk. Additional studies are needed to determine if a link or pattern between infrequent defecation and colon cancer actually exists.
The primary theory of those who believe that chronic constipation contributes to colorectal cancers is that increased waste transit time results in additional toxins being absorbed by the colon. These toxins may include carcinogenic materials which come from pesticides on foods, synthetically produced additives in food, and other sources. As fecal matter sits in the colon, water is absorbed from it and eventually, waste materials may also be absorbed back into the body to be reprocessed by the liver and colon. Whether or not these theories are accurate is still undetermined, although some studies have shown that those who have frequent bouts with constipation may have an increased risk of colon cancer.
It is also undetermined whether any potential link between infrequent defecation and colon cancer would be caused by the constipation itself, or by other factors common amongst those with this condition. Those who face colon cancer, especially those with no family history, are more likely to eat processed foods, be overweight, and not drink enough water. Fiber, which prevents constipation and keeps the colon moving smoothly, has been shown to decrease colorectal cancer risks in those who consume it regularly.
There have been additional studies which show opposite findings to the ones mentioned above. They indicate that those who have occasionally suffered from constipation had a lower incidence of colon cancer risk than those who defecated two or more times per day. Additional tests showed no linked between defecation and cancer risk.
Several factors must be taken into considering when determining ones risk for developing colon cancer. Family history plays a strong role, since the condition is often hereditary. Eating a diet high in fat and heavily processed foods also increases risk, as does dehydration. These factors combined with age and overall health may greatly impact the risk of developing cancer of any type.