Diarrhea And Endometriosis and Fibroids: What to Know

September 13, 2025

Diarrhea and Endometriosis and Fibroids: What to Know

If you live with endometriosis or uterine fibroids, you may notice bowel changes—especially around your period. For some, that means diarrhea, urgency, or cramping that feels different from a typical stomach bug. This guide explains why diarrhea can happen with these gynecologic conditions, how to tell when it’s a red flag, and what treatments—both at home and with your clinician—can help. Information and links below draw on trusted sources including the NIH, NIDDK, ACOG, and the FDA.

Why diarrhea can worsen around your period

During menstruation, the body releases prostaglandins—hormone-like chemicals that help the uterus contract and shed its lining. Prostaglandins don’t just act on the uterus; they also stimulate smooth muscle in the intestines. That can speed up gut motility and lead to looser stools, cramping, and sometimes nausea—especially on the first day or two of bleeding. The NIH’s MedlinePlus notes these prostaglandin effects as a common part of painful periods for many people, even without an underlying condition (MedlinePlus).

Endometriosis and the gut: common connections

Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus. It can involve the ovaries, peritoneum, and in some cases the bowel (often the rectosigmoid colon). When the bowel is affected, inflammation and scarring can trigger cyclical gastrointestinal symptoms—diarrhea, constipation, painful bowel movements, bloating, and rectal pain—that tend to flare around menstruation. The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) lists gastrointestinal symptoms such as diarrhea and constipation among common endometriosis complaints (NICHD).

Even without direct bowel lesions, endometriosis-related inflammation and pelvic pain can sensitize the gut–brain axis, resembling irritable bowel syndrome (IBS). Research suggests people with endometriosis experience IBS-like symptoms more often than those without endometriosis, which can complicate diagnosis and management. If your diarrhea follows a menstrual pattern or accompanies pelvic pain, it’s worth discussing with a clinician experienced in endometriosis.

Do fibroids cause diarrhea?

Uterine fibroids (leiomyomas) are noncancerous growths of the uterine muscle. The American College of Obstetricians and Gynecologists (ACOG) notes that fibroids most commonly cause heavy menstrual bleeding, pelvic pressure, and reproductive symptoms. Gastrointestinal effects are usually pressure-related—constipation or a sensation of incomplete bowel movements—especially when fibroids press on the rectum (ACOG: Uterine Fibroids).

Diarrhea isn’t a classic fibroid symptom. However, some people report looser stools during heavy bleeding days (likely prostaglandin-related) or intermittent bowel changes from pelvic pressure. If diarrhea is prominent, persistent, or unrelated to your cycle, consider other causes (infections, IBS, inflammatory bowel disease, celiac disease) and get evaluated.

When to seek care—red flags

Signs of dehydration: dizziness, very dry mouth, minimal urination, fast heartbeat
Black, maroon, or bloody stools
Fever, severe or worsening abdominal pain, or pain that is not typical for your cycle
Unintended weight loss or nighttime symptoms that wake you
Diarrhea lasting more than 3 days despite home care
New bowel symptoms after age 45, or a family history of colorectal disease

How clinicians evaluate diarrhea with pelvic conditions

Your clinician will ask about timing (cyclical vs constant), stool characteristics, diet, medications, and associated symptoms (pelvic pain, heavy bleeding). A pelvic exam and targeted imaging—often a transvaginal ultrasound for fibroids and ovarian pathology, sometimes MRI for deep endometriosis—help distinguish causes. Definitive diagnosis of endometriosis still relies on laparoscopy, though many are treated based on symptoms and imaging (ACOG: Endometriosis).

If infection or inflammatory bowel disease is suspected, stool tests and bloodwork may be ordered; colonoscopy is considered if alarm features, age-appropriate screening, or atypical patterns are present. The goal is to avoid missing a gastrointestinal disorder while also addressing gynecologic drivers of symptoms.

What you can do now: practical self-care

Hydrate: Take frequent sips of fluids. If you’re losing a lot of liquid, an oral rehydration solution helps replace electrolytes (NIDDK: Treating Diarrhea).
Gentle diet: Choose soluble fiber (bananas, oatmeal, rice), broths, and small, frequent meals. Limit alcohol, high-caffeine drinks, very spicy or greasy foods during flares.
Over-the-counter relief: Loperamide can reduce urgency and frequency; bismuth subsalicylate may help if mild and non-bloody. Follow labels and avoid antidiarrheals if you have high fever or blood in the stool.
Pain management: NSAIDs can lessen menstrual cramps by blocking prostaglandins and may indirectly reduce cramp-driven diarrhea; take with food and avoid if you have ulcers, kidney disease, or specific contraindications.
Heat and movement: A warm pack on the lower abdomen and gentle walking or stretching can reduce cramping.
Track patterns: Note stool changes across your cycle, diet triggers, and pain scores. Bring this diary to appointments—it’s invaluable for tailoring care.

Medical treatments that target the root cause

For endometriosis

Hormonal suppression: Continuous combined oral contraceptives, progestin-only pills, the levonorgestrel IUD, or contraceptive implants can reduce or stop menses, lowering prostaglandin surges and cyclical bowel symptoms (ACOG).
GnRH pathway agents: Elagolix (Orilissa) and combination therapies such as relugolix/estradiol/norethindrone (Myfembree) are FDA-approved for endometriosis pain and can lessen period-related flares by suppressing ovarian hormones; monitoring and “add-back” therapy help protect bone health (FDA: Elagolix approval; FDA: Myfembree endometriosis approval).
Surgery: Laparoscopic excision or ablation of endometriosis, including bowel lesions when present, can relieve pain and bowel dysfunction in selected patients; choose an experienced surgical team.

For fibroids

Bleeding control: The levonorgestrel IUD, tranexamic acid (Lysteda), and FDA-approved oral GnRH antagonist combinations—elagolix/estradiol/norethindrone (Oriahnn) and relugolix/estradiol/norethindrone (Myfembree)—reduce heavy menstrual bleeding due to fibroids, which may in turn lessen prostaglandin-driven diarrhea (FDA: Oriahnn approval; FDA: Myfembree fibroid approval).
Fibroid-focused procedures: Myomectomy, uterine artery embolization, radiofrequency ablation, or MRI-guided focused ultrasound can shrink or remove fibroids, which may relieve pressure-related bowel symptoms. Discuss risks, benefits, and fertility goals with your gynecologist (ACOG).

Choice of therapy depends on your symptoms, desire for pregnancy, other health conditions, and whether endometriosis, fibroids, or both are driving the picture. Many patients need a combined approach—bowel-calming strategies plus gynecologic treatment.

The bottom line

Diarrhea around your period is common, and endometriosis can amplify it—especially if the bowel is involved or if IBS overlaps. Fibroids more often cause constipation and pressure, but heavy bleeding may contribute to menstrual diarrhea for some. Keep a symptom diary, stay hydrated, use safe over-the-counter aids, and talk with a clinician about treatments that target the underlying condition. If you notice red flags like dehydration, blood in the stool, or persistent symptoms, seek care promptly.

Sources

MedlinePlus (NIH): Menstrual cramps and prostaglandins — https://medlineplus.gov/ency/article/001926.htm
NICHD (NIH): Endometriosis symptoms — https://www.nichd.nih.gov/health/topics/endometriosis/conditioninfo/symptoms
ACOG: Endometriosis FAQ — https://www.acog.org/womens-health/faqs/endometriosis
ACOG: Uterine Fibroids FAQ — https://www.acog.org/womens-health/faqs/uterine-fibroids
NIDDK (NIH): Treatment of Diarrhea — https://www.niddk.nih.gov/health-information/digestive-diseases/diarrhea/treatment
FDA: Oriahnn approval (fibroid-related heavy bleeding) — https://www.fda.gov/news-events/press-announcements/fda-approves-first-oral-treatment-management-heavy-menstrual-bleeding-associated-fibroids
FDA: Myfembree approval (fibroid-related heavy bleeding) — https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-treatment-management-heavy-menstrual-bleeding-associated-uterine
FDA: Elagolix approval for endometriosis pain — https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-first-oral-treatment-management-pain-associated-endometriosis
FDA: Myfembree approval for endometriosis pain — https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-first-oral-therapy-management-pain-associated-endometriosis