Rectal bleeding, known medically as hematochezia, is the passage of fresh blood through the anus, often mixed with stool. While this common symptom can stem from minor, easily treatable conditions, it must always be evaluated by a medical professional. This assessment is necessary to determine the source of the bleeding and rule out serious underlying issues. This guide explains the necessary steps for triage and identifies the specialists best equipped to manage the various causes.
Immediate Triage and Emergency Care
Rectal bleeding requires immediate emergency care if it indicates an acute, life-threatening situation. Go to the nearest emergency room or call emergency services if the bleeding is continuous or heavy, such as soaking the toilet bowl or passing large blood clots. Signs of potential shock also signal immediate action. These include feeling dizzy or lightheaded, confusion, a rapid heart rate, or cold, clammy skin. Seek emergency care if the bleeding is accompanied by persistent, severe abdominal pain, which can indicate a more serious internal issue.
Identifying the Right Specialist
For non-emergency cases, the first step is typically a consultation with your Primary Care Provider (PCP). The PCP performs an initial physical examination, takes a detailed history, and orders basic tests like blood work or stool samples. They can often diagnose and manage common, benign causes of bleeding, such as minor hemorrhoids or anal fissures. If the bleeding is persistent, the cause is unclear, or a problem higher up in the digestive tract is suspected, a referral to a specialist is necessary.
A Gastroenterologist (GI) is the expert in the entire digestive system, including the esophagus, stomach, small intestine, and colon. They perform internal visualization tests, such as colonoscopies, to identify and treat sources of bleeding throughout the lower gastrointestinal tract.
A Proctologist or Colorectal Surgeon specializes specifically in conditions of the colon, rectum, and anus. These specialists are consulted when bleeding is localized to the anal or rectal area and may require a surgical procedure. They manage conditions like complex anal fissures, fistulas, and hemorrhoids unresponsive to conservative treatment.
Common Causes of Rectal Bleeding
The color of the blood often provides a clue about its origin within the gastrointestinal tract. Bright red blood suggests the source is close to the anus, in the lower colon or rectum. This is frequently caused by external hemorrhoids (swollen veins around the anus) or anal fissures (small tears in the lining, often caused by hard stools).
Bleeding originating higher up the colon is typically darker red or maroon, as the blood has been partially digested during transit. Causes in this area include diverticulosis—small pouches that bulge from the colon wall and can sometimes bleed. Inflammatory Bowel Disease (IBD), such as Crohn’s disease or ulcerative colitis, causes inflammation and ulcers in the colon that lead to bleeding.
More serious causes that must be ruled out are growths in the colon, such as polyps or colorectal cancer. Polyps are fleshy growths on the intestinal lining, and some types have the potential to become malignant. Colorectal cancer can cause bleeding that may be bright red or darker, and its presence necessitates a full diagnostic workup.
Diagnostic Procedures and Next Steps
Once with a specialist, the diagnostic process begins with a detailed history and physical examination. A Digital Rectal Exam (DRE) involves the physician inserting a gloved, lubricated finger into the rectum to feel for abnormalities like hemorrhoids or tumors. If a source near the anal opening is suspected, an anoscopy may be performed, using a small, rigid tube with a light to visualize the anal canal directly.
For bleeding not obviously from the anal canal, internal visualization of the colon is necessary. A flexible sigmoidoscopy uses a flexible, lighted tube to examine the rectum and the lower, S-shaped portion of the colon. This procedure is suitable for assessing localized lower tract issues like proctitis.
The most comprehensive procedure is the colonoscopy, which uses a longer, flexible tube and camera to examine the entire large intestine. This is the standard for evaluating unexplained bleeding or when colorectal cancer risk factors exist. A colonoscopy allows the specialist to identify the precise source of bleeding and often remove polyps or take tissue samples (biopsies) during the same procedure.