Cancer is the transformation of normal cells. These transformed cells grow and multiply abnormally. Cancers are dangerous because of their uncontrolled growth and potential for spread. Cancer overwhelms healthy cells, tissues, and organs by taking their oxygen, nutrients, and space.
In colon cancer, these abnormal cells grow and eventually spread through the colon wall to involve the adjacent lymph nodes and organs. Ultimately, they spread (metastasized) to distant organs such as the liver, lungs, brain, and bones.
Most colon cancers are adenocarcinoma tumors that develop from the glands lining the colon's inner wall. These cancers, or malignant tumors, sometimes are referred to as colorectal cancer, reflecting the fact that the rectum, the end portion of the colon, also can be affected. Anatomic differences in the rectum as compared to the rest of the colon require that doctors separately recognize these areas.
Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder.
IBS-C is irritable bowel syndrome with constipation. Symptoms most common with IBS-C include:
IBS-D is irritable bowel syndrome with diarrhea. Symptoms most common with IBS-D include:
In the United States, one in 17 people will develop colorectal cancer. According to reports from the National Cancer Institute, colorectal cancer is the third most common cancer in U.S. men. Colorectal cancer is the second most common cancer in US women of Hispanic, American Indian/Alaska Native, or Asian/Pacific Islander ancestry, and the third most common cancer in white and African American women.
The overall incidence of colorectal cancer increased until 1985 and then began decreasing at an average rate of 5% per year in people 50 and older from 2009-2013 (available data). Deaths from colorectal cancer rank third after lung and prostate cancer for men and third after lung and breast cancer for women. Death statistics from colon cancer vs. rectal cancer is not clear as an estimated 40% of rectal cancers are misdiagnosed as colon cancer (another reason for lumping them together numerically).
IBS is not contagious, inherited, or cancerous. It occurs more often in women than in men, and the onset occurs before the age of 35 in about half of the cases. IBS occurs in 5% to 20% of children.
Symptoms of colon cancer may not be present or be minimal and overlooked until it becomes more severe. Cancer screening tests for colon cancer thus are important in individuals 50 and older. Cancer of the colon and rectum can exhibit itself in several ways. If you have any of these symptoms, seek immediate medical help. You may notice bleeding from your rectum or blood mixed with your stool. It usually, but not always, can be detected through a fecal occult (hidden) blood test, in which samples of stool are submitted to a lab for detection of blood.
If the tumor gets large enough, it may completely or partially block your colon. You may notice the following symptoms of bowel obstruction:
Studies suggest that the average duration of symptoms (from onset to diagnosis) is 14 weeks.
IBS affects each person differently. The most common symptom of IBS in adults and children is abdominal discomfort or pain. Other common signs and symptoms include:
Indigestion affects up to 70% of people with IBS, however, it is not a symptom of IBS.
Signs and symptoms that are NOT IBS, but should still be brought to the attention of a health-care professional since they may be signs and symptoms of other conditions include:
Most colorectal cancers arise from adenomatous polyps. Such polyps are comprised of excess numbers of both normal and abnormal appearing cells in the glands covering the inner wall of the colon. Over time, these abnormal growths enlarge and ultimately degenerate to become adenocarcinomas.
People with certain genetic abnormalities develop what are known as familial adenomatous polyposis syndromes. Such people have a greater-than-normal risk of colorectal cancer. In these conditions, numerous adenomatous polyps develop in the colon, ultimately leading to colon cancer. There are specific genetic abnormalities found in the two main forms of familial adenomatous polyposis. The cancer usually occurs before age 40 years. Adenomatous polyposis syndromes tend to run in families. Such cases are referred to as familial adenomatous polyposis (FAP). Celecoxib (Celebrex) has been FDA approved for FAP. After six months, celecoxib reduced the mean number of rectal and colon polyps by 28% compared to placebo (sugar pill) 5%.
Another group of colon cancer syndromes, termed hereditary nonpolyposis colorectal cancer (HNPCC) syndromes, also runs in families (genetic, inherited). In these syndromes, colon cancer develops without the precursor polyps. HNPCC syndromes are associated with a genetic abnormality. This abnormality has been identified, and a test is available. People at risk can be identified through genetic screening. Once identified as carriers of the abnormal gene, these people require counseling and regular screening to detect precancerous and cancerous tumors. HNPCC syndromes are sometimes linked to tumors in other parts of the body.
Also at high risk for developing colon cancers are people with:
The risk of colon cancer increases two to three times for people with a first-degree relative (parent or sibling) with colon cancer. The risk increases more if you have more than one affected family member, especially if the cancer was diagnosed at a young age.
Other factors that may affect your risk of developing a colon cancer include:
The cause of irritable bowel syndrome is currently unknown. It is thought to result from a combination of abnormal gastrointestinal (GI) tract movements, increased awareness of bodily functions, and a disruption in the communication between the brain and the GI (digestive) tract.
Risk factors for IBS include:
Anxiety or depression may accompany IBS, though these have not been found to be a direct cause of IBS.
Call your doctor or other healthcare professional if you have any of these signs and symptoms.
Go to your nearest Emergency Department immediately if you have any of these symptoms.
If you have any of the symptoms of irritable bowel syndrome, or if you have IBS and experience unusual symptoms, call your doctor for consultation. Go to a hospital emergency department if problems are severe and/or come on suddenly.
Irritable bowel syndrome or IBS is a functional disorder of the digestive (gastrointestinal, GI) tract with symptoms of bloating, abdominal cramping and pain, diarrhea, constipation, and nausea.
Common IBS triggers include gluten, foods high in fat, stress and anxiety, menstruation, and some medications.
