Uterine fibroids (leiomyomas) are non-cancerous growths composed of muscle and fibrous tissue that develop in or on the walls of the uterus. They range in size from tiny seedlings to bulky masses that can expand the uterus. Fibroids are common, affecting many women by age 50, and can cause symptoms like heavy menstrual bleeding, pelvic pressure, and abdominal discomfort. This article addresses whether these growths can cause bleeding from the rectum.
The Connection Between Fibroids and Rectal Bleeding
Fibroids do not directly cause rectal bleeding because the uterus, where fibroids grow, is separate from the lining of the rectum and anus. Rectal bleeding is almost always a sign of an issue within the gastrointestinal (GI) tract itself. The presence of a fibroid does not create a lesion or tear in the rectal tissue that would lead to bleeding.
If a woman with fibroids experiences rectal bleeding, the two conditions are most likely co-occurring, caused by a separate, underlying GI issue. However, fibroids can indirectly contribute to conditions that do cause bleeding, especially when they grow large. This indirect relationship is based on the close anatomical proximity of the reproductive and digestive organs within the pelvic cavity.
Gastrointestinal Symptoms Caused by Fibroid Pressure
The uterus is closely surrounded by other pelvic structures, including the bladder and the rectum and colon. Fibroids, particularly those on the back wall of the uterus (subserosal fibroids), can exert physical pressure on the adjacent rectum. This mechanical compression interferes with the normal movement of stool through the lower colon.
When stool passage is hindered, it often leads to chronic constipation and difficulty passing a bowel movement. Patients may report straining during defecation or a persistent feeling of incomplete evacuation. This repeated straining due to fibroid-induced constipation can then lead to secondary complications in the anal area.
Chronic straining is a common factor in the development of hemorrhoids, which are swollen veins in the anus or lower rectum. Internal hemorrhoids often cause painless, bright red rectal bleeding when their surface is damaged by hard stool or pressure. Thus, the fibroid can create the condition—severe constipation—that results in bleeding from hemorrhoids.
Common Non-Fibroid Causes of Rectal Bleeding
Since fibroids are only an indirect cause of bleeding, any observed blood should prompt an investigation into other common sources within the lower GI tract. Hemorrhoids are the most frequent cause of rectal bleeding, especially when the blood is bright red, coating the stool or appearing on toilet paper. They are swollen blood vessels that bleed easily due to straining or hard stools.
Another common source of bright red blood is an anal fissure, a small tear in the thin lining of the anal canal. Fissures are caused by passing large or hard stools and are typically accompanied by sharp pain during or immediately following a bowel movement. Bleeding from these conditions is usually minor and often resolves with conservative management.
More serious causes of bleeding must also be considered:
- Diverticulosis, which occurs when small pouches (diverticula) form in the colon wall, causing bleeding if a blood vessel ruptures.
- Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, involves chronic inflammation that can lead to ulcers and bloody diarrhea.
- Colorectal polyps, which are growths on the colon lining that can bleed and may become malignant over time.
- Colorectal cancer, an important cause of rectal bleeding, particularly in older individuals.
Bleeding from these sources may be intermittent and sometimes accompanied by other symptoms like a change in bowel habits or unexplained weight loss.
When to Seek Medical Evaluation
Any instance of rectal bleeding warrants a consultation with a physician to determine the exact origin. Even with a known diagnosis of uterine fibroids, a complete medical evaluation is necessary to rule out other potential causes. A doctor can perform a physical examination and may recommend diagnostic tests to pinpoint the bleeding source.
Certain “red flag” symptoms suggest the need for more urgent medical attention. Seek immediate care if the bleeding is heavy, continuous, or if you pass a large volume of blood or blood clots. The appearance of black or tarry stools (melena) suggests bleeding from higher up in the gastrointestinal tract and requires prompt evaluation. Other concerning signs include unexplained weight loss, severe abdominal pain, or symptoms of significant blood loss, such as dizziness or fainting.