Finding blood in your stool can be concerning, especially when it coincides with your menstrual period. This article explores various reasons why blood might appear in stool during menstruation, from common, benign causes to more specific conditions that require attention.
Menstrual Cycle’s Influence on Digestive System
Hormonal shifts during the menstrual cycle can impact the digestive tract. During menstruation, the body releases prostaglandins, which stimulate uterine contractions to shed the uterine lining.
Prostaglandins also influence smooth muscles in the gastrointestinal tract, increasing bowel motility. This can lead to altered bowel habits like diarrhea or more frequent bowel movements during the premenstrual and menstrual phases. A drop in progesterone levels just before menstruation can also stimulate digestion. These changes, including straining or loose stools, can irritate lower digestive tissues, potentially causing minor bleeding.
Differentiating the Source of Blood
Observing blood characteristics offers clues about its origin, though it is not a substitute for medical diagnosis. Menstrual blood is typically bright to dark red, sometimes mixed with mucus, and seen on sanitary products or after urination. Gastrointestinal blood presents differently based on its source.
Bright red blood on stool or toilet paper usually indicates bleeding from the lower digestive system, such as the colon, rectum, or anus. Darker red or maroon blood often suggests bleeding from higher in the colon or small intestine. Black, tarry stools, termed melena, signify bleeding from the upper gastrointestinal tract, like the stomach, where blood has been digested.
Common Coincidental Causes of Rectal Bleeding
Rectal bleeding can stem from common conditions that may coincidentally occur during a menstrual period, and sometimes their symptoms can be exacerbated by the digestive changes associated with the cycle. Hemorrhoids, swollen veins in or around the anus, frequently cause bright red blood, often due to straining or irritation.
Anal fissures are small tears in the anal lining, often from hard stools or prolonged diarrhea. They cause sharp pain during or after a bowel movement, with bright red blood on stool or toilet paper. While painful, they are generally not serious and often heal with conservative measures.
Diverticulosis, where small pouches form in the colon, can lead to bleeding. Bleeding from diverticular disease ranges from bright red to darker blood. Inflammatory Bowel Disease (IBD), including Crohn’s disease and ulcerative colitis, also causes rectal bleeding. IBD symptoms often include abdominal pain, diarrhea, fatigue, and blood in the stool. Gastrointestinal infections can also cause bloody diarrhea.
Conditions Directly Linking Menstrual Cycle and Bowel Bleeding
Some conditions directly link the menstrual cycle to blood in the stool. Bowel endometriosis is a key example, where uterine-lining-like tissue grows on or inside the intestines or rectum. This misplaced tissue responds to hormonal fluctuations, thickening and bleeding with the uterine lining during menstruation.
When endometrial implants are on the bowel, they can bleed cyclically, causing blood in the stool during the menstrual period. This condition also causes severe pain during bowel movements, cyclical constipation, diarrhea, and bloating. The pain is often described as sharp and can be particularly intense during menstruation.
Uterine fibroids do not typically cause direct rectal bleeding. However, large fibroids can pressure nearby organs like the colon or rectum. This pressure can interfere with bowel function, leading to constipation. While rare, severe constipation caused by fibroids could indirectly exacerbate existing issues like hemorrhoids, potentially leading to minor bleeding.
When to Seek Medical Attention
While some blood in stool is benign, it is always important to consult a healthcare professional for proper evaluation. Indicators for urgent medical attention include persistent bleeding outside the menstrual period or continuing for several cycles.
Heavy bleeding, such as red toilet water or large blood clots, warrants immediate medical evaluation. Dark, tarry stools (melena) also require prompt assessment, indicating bleeding higher in the digestive tract. Accompanying symptoms like severe abdominal pain, unexplained weight loss, persistent changes in bowel habits (new constipation or diarrhea), fever, dizziness, or extreme fatigue are significant red flags. New onset rectal bleeding, especially for individuals over 40 to 50 years of age, should be evaluated to rule out serious underlying conditions.