Rectal bleeding, medically known as hematochezia, is the passage of fresh blood from the anus and is a symptom that warrants medical evaluation. This bleeding can present as bright red blood on toilet paper, streaks on the stool, or blood visible in the toilet bowl. Rectal bleeding is not a diagnosis itself, but an indicator of an underlying condition within the lower gastrointestinal tract. A healthcare professional must determine the exact source of the bleeding to identify the necessary treatment.
Common Causes of Rectal Bleeding
The most frequent cause of rectal bleeding is hemorrhoids, which are swollen veins located inside or outside the rectum and anus. Hemorrhoids become engorged due to increased pressure from straining, chronic constipation, or pregnancy. They typically produce bright red blood that is not mixed into the stool. Another common cause is an anal fissure, a small tear or cut in the lining of the anal canal that causes sharp pain during defecation along with small amounts of bright red blood.
Bleeding originating higher in the colon often presents as darker red blood, sometimes mixed with the stool. This can indicate diverticulosis, a condition where small pouches (diverticula) bulge from the colon wall. If a blood vessel within a pouch erodes, it can cause significant, often painless bleeding. Inflammatory Bowel Disease (IBD), which includes Crohn’s disease and Ulcerative Colitis, causes inflammation and ulceration in the digestive tract lining, leading to bloody diarrhea and mucus.
Less common, but more serious, causes include polyps and colorectal cancer, which can cause intermittent or occult bleeding that may not be immediately visible. Colorectal polyps are growths on the inner lining of the colon or rectum; while most are benign, some types can progress into cancer over time.
Diagnostic Procedures for Locating the Source
The diagnostic process begins with a detailed patient history regarding the color, quantity, and frequency of the blood, and associated symptoms like pain or changes in bowel habits. This is followed by a physical examination, including a Digital Rectal Exam (DRE). During a DRE, a gloved, lubricated finger is inserted into the rectum to check for masses, tenderness, or internal hemorrhoids, helping localize the source to the anal or rectal area.
If the bleeding originates low in the tract, an anoscopy or proctoscopy may be performed. Anoscopy uses a short, rigid tube with a light source to visualize the anal canal and lower rectum, detecting hemorrhoids or fissures. A flexible sigmoidoscopy extends this view, using a flexible tube to examine the rectum and the lower part of the colon.
The standard procedure for evaluating the entire large intestine is the colonoscopy. This uses a long, flexible tube equipped with a light and a camera to examine the colon from the rectum to the cecum. Colonoscopy is often necessary to rule out serious conditions like polyps or cancer higher up in the colon. Stool tests and blood work may also be ordered to check for hidden blood, anemia, or inflammation markers.
Specific Treatments for Minor Causes
Treatment for minor causes often begins with conservative, non-surgical approaches focusing on dietary and lifestyle modifications. Increasing dietary fiber intake (25 to 35 grams per day) and ensuring adequate hydration helps soften stools, which reduces straining and irritation of hemorrhoids or fissures. Avoiding prolonged sitting on the toilet is also recommended, as this increases pressure on the rectal veins.
Topical treatments such as creams, ointments, or suppositories containing hydrocortisone or witch hazel can temporarily relieve the swelling, pain, and itching associated with external hemorrhoids. For an anal fissure, treatment involves relaxing the anal sphincter muscle to allow the tear to heal. This is often accomplished by soaking the area in a warm sitz bath for 10 to 15 minutes several times a day. Prescription nitroglycerin ointment may also be applied to increase blood flow and promote healing.
If conservative measures fail for internal hemorrhoids, office-based procedures are the next step. These minimally invasive treatments are effective for the majority of non-complicated hemorrhoidal bleeding.
Office-Based Procedures
- Rubber band ligation: A small band is placed around the base of the hemorrhoid to cut off its blood supply, causing the tissue to shrink and fall off within a week.
- Sclerotherapy: A chemical solution is injected into the hemorrhoid to cause scar tissue formation, shrinking the vein.
- Infrared photocoagulation: Heat is used to achieve a similar result by shrinking the hemorrhoid tissue.
Medical Interventions for Underlying Diseases
When the source of bleeding is a complex underlying disease, treatment shifts to specialized medical management aimed at controlling the condition. For Inflammatory Bowel Disease (IBD), the goal is to reduce inflammation in the colon lining to stop the bleeding. This typically involves a specialized medication regime, which may include immunosuppressants, aminosalicylates, or biologic therapies that target specific inflammatory pathways.
If rectal bleeding is caused by colorectal cancer, a multi-faceted treatment plan is implemented. Treatment often starts with surgery to remove the malignant tumor and surrounding lymph nodes. Depending on the cancer’s stage, this may be followed by chemotherapy or radiation therapy to shrink tumors. For severe and uncontrolled bleeding, such as from complicated diverticulitis or high-grade hemorrhoids, surgical intervention may be required. A formal hemorrhoidectomy, for example, permanently removes the source of the hemorrhage. These complex conditions require ongoing care and surveillance managed by a multidisciplinary team of specialists.