Rectal cancer manifests in diverse ways, with nearly one-third of patients showing no abnormalities in the early stages. Therefore, constant vigilance is essential. Particular attention should be paid to the following changes in bowel movements:
1. Painless bloody stool
Typically, in the early stages of rectal cancer, friction between stool and the tumor can rupture blood vessels on the tumor surface, causing bleeding. This results in distinct, fresh blood streaks on one side of the stool. This symptom is often mistaken for hemorrhoids, making self-diagnosis difficult and leading to clinical misdiagnosis in some cases!
As rectal cancer progresses, the nature of bloody stools may change. Patients may pass a mixture of blood, feces, and mucus, with the blood typically appearing dark red. When the cancer advances to the point where local tumor tissue erodes and necrotizes, patients may also pass bloody pus stools—feces with a foul odor containing blood clots or necrotic tissue!Therefore, if you suddenly pass painless bloody stools mixed with feces or notice an unusually foul odor in your stool, this could signal the onset of rectal cancer.
II. Abnormal Bowel Habits
If you experience an unexplained increase in bowel movements lasting over two weeks, accompanied by recurrent diarrhea, incomplete evacuation, or a persistent urge to defecate, this may also indicate rectal cancer.
Once a rectal tumor forms, both the tumor itself and its secretions strongly irritate the intestinal mucosa. This alters bowel habits, causing pseudo-diarrhea. In the early stages, this pseudo-diarrhea often occurs shortly after waking in the morning.
III. Intestinal Stenosis and Obstruction Symptoms
Rectal tumors grow continuously as cancer cells divide, infiltrating circumferentially around the intestinal wall and progressively narrowing the lumen. Tumors developing at the rectosigmoid junction are particularly prone to causing obstruction symptoms, manifesting as narrowed stool consistency, straining during defecation, constipation, abdominal pain, and bloating.As defecation difficulties worsen, a cord-like abnormal mass may sometimes be palpable in the patient's lower abdomen;
IV. Anal Pain
Patients with low-lying rectal cancer may experience abnormal anal pain once the cancer progresses and infiltrates the anal canal. This pain intensifies and persists longer as the disease advances.Once the tumor involves the anal sphincter muscles, patients may not only experience pain but also gradually develop anal incontinence and difficulty controlling bowel movements!
For individuals with a family history of colorectal cancer, those over 45 years old, or those with a history of chronic intestinal diseases, it is essential to monitor bodily changes closely and undergo regular colorectal cancer screenings. Common screening methods include digital rectal examination (DRE) and colonoscopy.