Rectal bleeding is a fairly common complaint. It may present in different ways: blood mixed with stool, blood noticed on the toilet bowl or in the water, or blood on toilet paper after wiping. Especially when the blood is bright red, the source is usually assumed to be the anus or rectum (the final portion of the large intestine just before the anus).
Many benign and malignant conditions of the colon, rectum, and anus can cause rectal bleeding. However, one critical point must be emphasized: In any patient presenting with rectal bleeding, malignant diseases of the colon, rectum, or anus must be ruled out.
Finding a benign condition (such as hemorrhoids) during examination is not enough to eliminate the suspicion of cancer. This is because benign anorectal conditions are very common in the general population. For instance, a patient may present with bleeding that is assumed to be due to hemorrhoids, while the actual cause may be a tumor located higher in the rectum. Unfortunately, it is not uncommon for such patients to be diagnosed at a late stage — sometimes after months of using hemorrhoid treatments.
How Is Cancer Ruled Out in Patients With Rectal Bleeding?
This is done through digital rectal examination (DRE) and endoscopic evaluation. The extent of endoscopy depends on the patient’s age and individual risk factors.
For example, in individuals under the age of 45 who have no risk factors for colorectal cancer and are found to have a benign condition that could explain the bleeding, it may be sufficient to perform a limited endoscopic examination of the rectum and anus. This procedure is called a rectoscopy.
