Based on PubMed | Can endometrial cancer cause blood in the stool?

Endometrial cancer does not typically cause blood in the stool; its hallmark symptom is abnormal vaginal bleeding. Blood seen with bowel movements is more often due to gastrointestinal conditions such as hemorrhoids, anal fissures, inflammatory bowel disease, diverticulosis, or colorectal polyps and cancer. ^{[1] [2]}

Typical Symptoms of Endometrial Cancer

• The most common early sign is abnormal vaginal bleeding (bleeding after menopause, bleeding between periods, or unusually heavy/prolonged bleeding). ^{[1] [2]}
• Other possible symptoms include pelvic pain and watery or bloody vaginal discharge. ^{[2] [3]}
• Because vaginal bleeding is such a recognizable sign, many cases are detected early and can be treated effectively. ^[2]

When Blood in Stool Could Be Linked to Endometrial Cancer

While uncommon, there are a few scenarios where endometrial cancer can be associated with rectal or colonic bleeding:

• Metastasis to the bowel: Rarely, endometrial tumors (including stromal sarcomas or carcinosarcomas) can spread to the colon or rectum, which may present as rectal bleeding. ^{[4] [5]}
• Direct involvement via endometriosis transformation: Extremely rare cases have described endometrial-type tissue in the rectum (from endometriosis) transforming into carcinoma, which can mimic rectal cancers and may bleed. ^{[6] [7]}
• Treatment-related rectal injury: Pelvic radiation for uterine cancers can cause late rectal complications (radiation proctitis) and bleeding or fistulas between the rectum and vagina. ^{[8] [9] [10]}

These situations are uncommon and usually occur in advanced or previously treated disease rather than at first presentation. ^{[8] [4]}

Common Causes of Blood in the Stool

Most cases of blood in the stool have gastrointestinal causes, not gynecologic origins. Frequent culprits include diverticulosis/diverticulitis, inflammatory bowel disease (ulcerative colitis, Crohn’s), colonic polyps, and colorectal cancer, as well as benign anorectal sources like hemorrhoids and fissures. ^{[11] [12]} Evaluations typically start with endoscopy (colonoscopy) to find the bleeding source. ^[12]

Practical Guidance

• If you notice blood in your stool, it’s important to seek medical care promptly because bleeding can signal conditions that need timely treatment, including colorectal cancer. ^{[12] [11]}
• If you have a history of endometrial cancer especially if you received pelvic radiation or if you experience new gastrointestinal symptoms along with gynecologic signs (like abnormal vaginal bleeding), your clinician may consider both GI and gynecologic evaluations. ^{[8] [1]}
• Persistent or heavy rectal bleeding, anemia, abdominal pain, unexplained weight loss, or changes in bowel habits warrant urgent assessment. ^{[12] [11]}
• In the context of any cancer care, blood in the stool should be reported immediately, since bleeding can indicate complications that merit urgent review. ^[13]

Bottom Line

• Blood in the stool is not a typical symptom of endometrial cancer; abnormal vaginal bleeding is. ^{[1] [2]}
• Rare exceptions exist where endometrial tumors involve the bowel or where treatment causes rectal injury leading to bleeding. ^{[4] [8] [5]}
• Most rectal bleeding stems from gastrointestinal causes and should be evaluated with GI-focused tests like colonoscopy. ^{[12] [11]}