The symptoms of a colon tumor can vary significantly from patient to patient, and depend on the type and location of the tumor. Some patients experience few symptoms or even none at all, and the tumor is only discovered through a routine colonoscopy. Others suffer from changes in bowel movements, abdominal pain, bloody stools, and other physical symptoms. A colon tumor can be benign, meaning that it is not cancerous, or malignant, meaning that it is cancerous. A biopsy of the tumor is typically the only way to determine which type it is.
Blood in the stools can indicate the presence of a colon tumor, although the presence of blood in stool can indicate other conditions, as well. Bleeding from hemorrhoids or minor rectal tears is usually bright red, while bleeding from a colon tumor is typically darker and may look like coffee grounds. Certain foods and medications can mimic the appearance of blood in the stools, including iron supplements, beets, and blueberries. Those who suspect that they are passing bloody stools should contact a physician immediately to determine their underlying cause.
The presence of a colon tumor can cause changes in bowel habits. In some, it can cause loose stools or bouts of diarrhea. In others, it may cause constipation and bowel movements that are difficult to pass. Urge incontinence (accidental bowel movements) or anal leakage can also occur.
Abdominal pain is also a possible symptom of a colon tumor, but like blood in the stool, it has many other potential causes. Typically, colon tumors cause pain on the left side of the abdomen. Appendicitis, diverticulitis, and even heartburn can also cause pain in this area. The pain may be accompanied by nausea, vomiting, loss of appetite, or unexplained weight loss. Abdominal pain, especially on the left side, should be evaluated by a physician.
The location of a tumor can affect symptoms as well. A tumor in the left side of the colon is more likely to cause bowel obstruction, which may lead to the bloody stools, abdominal pain, and changes in bowel habits. The right side of the colon has more space, allowing a colon tumor to grow larger. When the tumor gets too large, it can cut off blood supply and result in iron deficiency, which is called anemia. Symptoms of anemia include fatigue, shortness of breath, and weakness.
Typically, a colon tumor doesn’t cause symptoms until it has reached a certain stage. Tumors are more common in older adults, so doctors recommend routine colonoscopies beginning at age 50 for those without a history of colon problems. Diagnosing the tumor early can increase the chances of successful treatment.