Rectal symptoms, such as pain or bleeding, often cause immediate concern about serious conditions like cancer. This reaction is understandable, given the overlap in how minor and major health issues can present in the lower digestive tract. However, most rectal symptoms are caused by benign and common conditions, most frequently hemorrhoids. Understanding the distinct characteristics of symptoms associated with hemorrhoids versus those linked to colorectal cancer provides clarity. Only a medical professional can provide a definitive diagnosis, but knowing the typical presentations can inform the urgency of seeking an evaluation.
Symptoms Typically Associated With Hemorrhoids
Hemorrhoids are swollen veins located in the lower rectum and anus. The most common symptom is painless bleeding, usually manifesting as bright red blood. This fresh blood is typically observed on the toilet paper after wiping, streaking the stool, or lightly dripping into the toilet bowl following a bowel movement. The bright color indicates the blood originates from a source close to the anal opening.
External hemorrhoids, located under the skin around the anus, can cause discomfort, pain, and itching, especially when irritated or thrombosed. A thrombosed hemorrhoid occurs when a blood clot forms inside the vein, resulting in a sudden, hard, and very painful lump near the anus. Internal hemorrhoids, which lie inside the rectum, are usually painless but can protrude through the anal opening, causing irritation and a feeling of incomplete evacuation.
Symptoms Typically Associated With Colorectal Cancer
Colorectal cancer arises from the uncontrolled growth of cells in the colon or rectum. A significant indicator is a persistent and unexplained change in bowel habits, which may include new constipation, lingering diarrhea, or a noticeable narrowing of the stool’s diameter. These changes reflect a mass or obstruction forming within the colon.
Bleeding associated with colorectal cancer often originates higher up in the digestive tract. This blood may be dark red or black, causing the stool to appear tarry, or it may be mixed in with the stool, making it less obvious. Colorectal cancer can also lead to systemic signs not seen with hemorrhoids, such as unexplained fatigue or weakness caused by chronic blood loss leading to anemia. A person may also experience persistent abdominal discomfort, cramping, or unintentional weight loss.
Key Distinctions in Symptom Presentation
The color and location of the blood are the most straightforward distinguishing features. Hemorrhoidal bleeding is almost always bright red and separate from the stool, originating from the perianal area. Conversely, blood from a cancerous lesion is more likely to be dark, mixed into the stool, or only detectable through chemical testing, indicating an origin higher up in the colon.
Pain also differs significantly. Hemorrhoid pain is generally sharp, localized to the anal area, and often related to passing stool or a specific event like thrombosis. Cancer-related discomfort is more commonly described as persistent, vague abdominal cramping or a persistent feeling of needing to have a bowel movement even after using the toilet.
The persistence of the underlying issue is another difference. Hemorrhoid symptoms often fluctuate, improving with conservative treatment or resolving on their own. In contrast, symptoms caused by a cancerous growth tend to be unremitting and worsen gradually.
Systemic symptoms are rarely caused by hemorrhoids. Unexplained weight loss—losing body weight without dieting or increased exercise—is a strong warning sign for cancer. Similarly, persistent fatigue not relieved by rest and linked to anemia from chronic internal bleeding is characteristic of colorectal cancer.
What Happens During a Medical Evaluation
Any instance of rectal bleeding or a persistent change in bowel habits warrants a medical consultation, as only a healthcare provider can identify the source. The evaluation typically begins with a thorough medical history and a physical examination, including a digital rectal exam (DRE) to check for lumps or abnormalities in the lower rectum. An anoscopy may also be performed, using a small, rigid, lighted tube to visually inspect the anal canal and lower rectum for hemorrhoids or fissures.
If the cause is not immediately clear, or if a patient has risk factors, further diagnostic testing is recommended. Stool tests, such as the fecal immunochemical test (FIT), check for occult, or hidden, blood. The definitive diagnostic procedures are sigmoidoscopy, which examines the lower part of the colon, or a full colonoscopy, which views the entire colon and rectum. These procedures can visualize and biopsy any suspicious growths, providing a definitive diagnosis.