Signs and Findings of Colon Cancer: Symptoms You Shouldn’t Ignore
Colorectal cancer is one of the most common cancers worldwide and, at the same time, one of the ones that responds best to treatment when detected early. The problem is that many people do not identify signs and findings in time that could alert them. Knowing which changes in your body deserve attention can make a real difference in prognosis.
What is colon cancer and why is it important to detect it early?
Colon cancer starts in the large intestine, usually from abnormal growths called polyps. Over time, some of these polyps can become malignant. When detected in early stages, the five-year survival rate exceeds 90%.
Difference Between Colon Cancer and Colorectal Cancer
The term colorectal cancer includes both colon and rectal cancer. Although they share many characteristics, location can influence symptoms and treatment approach. In clinical practice, both are managed with similar screening and follow-up criteria.
Most common warning signs of colon cancer
Recognizing the first signs is key. These are the signs that appear most frequently and that should not be missed.
Blood in the stool or rectal bleeding
The presence of blood in the stool is one of the most important signs. It can be seen as visible red blood or as very dark or black stools, suggesting rectal bleeding or bleeding in a higher area of the intestine. Many people attribute it to hemorrhoids, but it should always be evaluated in consultation to rule out more serious causes.
Persistent changes in bowel habits
When there is a noticeable change in bowel habits and it is maintained for more than a few weeks, it is worth paying attention to. This is one of the most common findings in people with colorectal cancer.
Long-term diarrhea or constipation
Diarrhea that lasts longer than usual, persistent constipation, or alternation between the two may indicate that something is interfering with normal bowel transit. If these symptoms do not have a clear cause, such as an infection or a change in diet, they should be investigated.
Feeling of incomplete evacuation
The feeling that the bowel didn’t empty completely after going to the bathroom — also called tenesmus — is another finding that may be related to the presence of a mass in the rectum or colon.
Abdominal pain and frequent cramping
Abdominal pain that persists, cramping, or a feeling of gas that does not improve are signs that warrant evaluation. If abdominal pain occurs along with other symptoms, such as stool changes or bleeding, the likelihood of colorectal origin increases.
Unexplained weight loss
Losing weight without having changed your diet or level of physical activity is a warning sign in any cancer context. In colon cancer, unexplained weight loss may be due to the consumption of energy generated by the tumor or a decrease in the absorption of nutrients.
Persistent fatigue and weakness
Tiredness that does not improve with rest may be related to iron deficiency anemia. In some patients, this anemia is the only manifestation of slow, silent bleeding in the bowel. In this context, anemia is a relevant clinical finding and warrants an evaluation of the colon.
Early symptoms versus late-stage symptoms
In the early stages, colon cancer may not cause any discomfort. When signs such as blood in the stool or changes in bowel habits appear, the disease may already have a certain degree of progression. Therefore, screening in people without symptoms is as important as consulting in time when something changes.
Signs When Cancer Has Spread
If the disease progresses, additional symptoms may occur, such as pain in the upper right abdomen (which may suggest liver involvement), shortness of breath, jaundice, or more marked weight loss. At these stages, treatment is still possible, although it is usually more complex.
Colorectal cancer screening findings
Screening tests can find abnormalities even when there are no symptoms yet. This is the central pillar of prevention.
Polyps and adenomas: what they mean for your health
Adenomas are polyps with the potential to develop into cancer. Finding them during a colonoscopy does not mean that cancer already exists, but that there is a risk that must be managed with follow-up and, in many cases, removal in the same procedure. In this procedure.
Colonoscopy Results
Colonoscopy is the gold standard test for detecting colorectal cancer. It allows you to see directly inside the colon and rectum, take tissue samples, and remove polyps at the same time. A normal result in a person without risk factors usually indicates that the next test can be scheduled in ten years.
Fecal occult blood tests
A fecal occult blood test detects small amounts of blood that are not visible to the naked eye. It is a noninvasive screening option, recommended annually or biennially for people at average risk. A positive result does not confirm cancer, but it does indicate the need for a colonoscopy.
Sigmoidoscopy and computed tomography colonography
Sigmoidoscopy evaluates only the lower part of the colon and rectum. This is why it is less complete than colonoscopy, although it can be useful in certain clinical contexts. Computed tomography colonography, also known as virtual colonoscopy, produces detailed images of the colon without the need for sedation. Both are valid alternatives within screening programs. Within screening programs.
Risk factors that increase the likelihood of colon cancer
Age and family history
Age is one of the most important risk factors. Most cases are diagnosed in people over 50 years of age, although an increasing trend is seen in younger adults. Having a family history of colorectal cancer or polyps in first-degree relatives also increases the risk significantly.
People at high risk and in need of screening
People at high risk include those with a personal history of adenomas, inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease, or inherited syndromes such as familial adenomatous polyposis. In these cases, screening should start earlier and be repeated more frequently, according to the individualized medical evaluation.
When to see a doctor for possible signs
You don’t have to have all the symptoms to see you. If you notice blood in your stool, a persistent change in your bowel habits, abdominal pain without a clear explanation, unexplained weight loss, or fatigue that won’t subside, seek medical evaluation. Early detection is the most powerful tool against colorectal cancer.
Dr. Roberto García, a specialist in oncology and oncological surgery with training at the Faculty of Medicine of Panama and training at cancer centers in Santiago de Chile, Bogotá and New York, attends at The Panama Clinic, 21st Floor, Office 2121, in Panama City. His approach combines diagnostic accuracy with close and empathetic care, accompanying each patient from initial evaluation to follow-up.
If you have questions or would like an evaluation, you can write to [email protected] or call 6545-6968.
Frequently Asked Questions About Signs and Findings of Colon Cancer
¿Los pólipos del colon siempre causan síntomas?
No. Most polyps do not cause discomfort. For this reason, many are detected by chance during a routine colonoscopy. Identifying them early allows you to act before they progress.
¿La anemia puede ser un signo de cáncer de colon?
Yes. Iron deficiency anemia without a clear cause—especially in postmenopausal men and women—may be the only indication of silent bowel bleeding. In these cases, it is recommended to study the colon.
¿Qué pruebas detectan el cáncer colorrectal de forma temprana?
The main ones are colonoscopy, fecal occult blood test, sigmoidoscopy, and computed tomography colonography. The doctor will define which is the most appropriate according to each person’s age, history, and risk level.
¿Puedo tener cáncer de colon sin síntomas?
Yes, especially in the early stages. Many people with early colorectal cancer have no symptoms. This is the main reason why preventive screening is essential from the age of 45, or even earlier if there are risk factors.
Content reviewed by Dr. Roberto García, specialist in Oncology and Oncological Surgery.
To take care of your health, it is advisable to take seriously the issue of colon cancer: signs and findings.
