Can endometriosis cause pencil-thin stools?

Yes, endometriosis can be associated with pencil-thin stools, most often when disease affects the rectum or sigmoid colon, or when pelvic inflammation and scarring change how the bowel moves and empties. Bowel endometriosis commonly involves the rectum and sigmoid, and symptoms can include shifts between constipation and diarrhea, painful bowel movements (often worse around your period), bloating, and sometimes rectal bleeding. That said, pencil-thin stool is not specific to endometriosis. It can also occur with pelvic floor coordination problems, IBS-like bowel sensitivity, or inflammatory bowel disease, conditions that can overlap with endometriosis or mimic it.

Because a thin stool pattern can reflect narrowing, spasm, or altered motility, we look at the full picture: timing with your cycle, pain with bowel movements, bleeding, and any imaging findings. Our team’s evaluation focuses on distinguishing bowel endometriosis from common look-alikes and coexisting GI conditions. When appropriate, we use expertly interpreted ultrasound/MRI to map suspected disease, while recognizing that imaging cannot reliably exclude endometriosis. If this symptom is persistent or new for you, reach out to schedule a consultation so we can help you understand what’s driving it and which treatment options make sense, including excision when bowel involvement is suspected.