Four Surprising Facts You Should Know About Endometriosis

Endometriosis is a serious health issue that occurs when cells similar to the lining of the uterus (called the “endometrium”) grow in other areas of the body, such as the pelvis, ovaries or abdomen. Over time, the irritation caused by these cells can create scar-like tissue called adhesions that can twist and tie the organs into unnatural positions, causing severe pain and, in some instances, infertility.

“Some celebrities like Tia Mowry and Olivia Culpo have helped raise awareness of this invisible disease,” shares Barbara McGuirk, M.D., Director of Reproductive Surgery at RADfertility, and Program Director of the Endometriosis & Pelvic Pain Center. However, there’s still a lot of misinformation: “Millions still struggle without understanding what’s happening in their bodies,” Dr. McGuirk continues.

Below, we’ll cover four surprising facts about endometriosis and address some of your most burning questions, like “What does endometriosis feel like?”, endometriosis flare-ups, and GI symptoms (including diarrhea and menstrual changes), so you can feel informed and validated.

Fact #1: It’s Common—but Often Undiagnosed

Endometriosis impacts roughly 11% of individuals assigned female at birth. Unfortunately, many people with the condition report that diagnosis is severely delayed–anywhere between five and ten years from the onset of symptoms.

Cultural myths about “normal period pain,” overlapping GI or urinary symptoms, and limited access to specialized care all contribute to delays. Many also see multiple providers before someone connects the dots.

How an Endometriosis Specialist Can Make a Difference

Dr. McGuirk, who is a Board-Certified Reproductive Endocrinology and Infertility Specialist who works with endo patients, shares, “Many people incorrectly assume that their symptoms are normal, but nothing about chronic pain is ever normal.” 

An OB-GYN with endo experience takes a multi-pronged approach to diagnosis. They look at symptom history, perform a targeted pelvic exam and often use specialized imaging to make an informed diagnosis and support your treatment goals.

Fact #2: It Can Cause a Wide Range of Symptoms

Pelvic pain and heavy or irregular periods are often cited as the most common endometriosis symptoms, but they’re far from the only ones. Because endometrial tissue can grow in different areas, symptoms vary widely, and you may experience:

• Deep, cramping pelvic pain before and during your period
• Sharp or throbbing pain in the lower back, hips, or thighs
• Pain in the hip joint during menstruation
• Pain during or after sex
• Painful bowel movements or urination, including rectal pain with menstruation
• Constipation, diarrhea, or bloating (“endo belly”)
• Extreme fatigue, nausea, or infertility

Small Lesions, Big Impact

One of the most frustrating realities of endometriosis is that the severity of pain doesn’t always correlate with the amount of visible disease. Endometriosis is classified into four stages (I–IV) based on how widespread the lesions are, but, per Dr. McGuirk, that doesn’t always correspond with pain. She says, “The stage of endometriosis does not necessarily correspond to the severity of symptoms.”

That’s because where the tissue grows (near nerves, the bowel, bladder, or pelvic ligaments) and how deeply it infiltrates can matter more than how much of it there is.

What Does Endometriosis Feel Like?

Your symptoms may look and feel different compared to someone else’s, and that can make self-advocacy tricky. Though it is still helpful to have a frame of reference. Many describe endo pain as:

• Deep aching or cramping in the pelvis that starts before, or intensifies during, a period
• Sharp, stabbing, or throbbing episodes that can take your breath away
• Endometriosis lower back pain that radiates into the hips, buttocks, or thighs
• Pain in the hip joint during menstruation, especially with activity or prolonged sitting
• Dyspareunia (pain during or after sex) that may linger for hours or days
• Pain with bowel movements or urination, including rectal pain with menstruation or urgency when the bladder is full

If you experience any of these, you’re not “overreacting”—you’re describing a recognized symptom profile of endometriosis.

Another “Surprise” Symptom? Rectal Pain and Painful Bowel Movements

It’s not uncommon to have painful bowel movements, especially around your period, as some people have lesions near the bowel or rectovaginal septum (a thin wall of tissue that separates the rectum from the vagina).

Some people notice crampy rectal pressure, sharp pain with defecation, or even cyclical changes in bowel habits. Similarly, endometriosis around the bladder can create urgency, frequency, and pain when the bladder is full.

Fact #3: Fatigue and Mood Symptoms Can Be as Debilitating as Pain

Being told your pain is “normal” and enduring years of chronic health issues can take a serious toll on your mental health. One study found that individuals with endometriosis had an increased risk of developing major depression and anxiety disorders compared to those without it. 

Endometriosis and Extreme Tiredness

Fatigue and endometriosis often go hand in hand. Inflammation, anemia related to heavy periods, and disrupted sleep all drain energy. The result? Bone-deep fatigue that’s hard to shake off.

Fact #4: What You Eat Can Impact Your Symptoms

Inflammation and high estrogen levels can potentially worsen symptoms, but diet can help manage both. Dr. McGuirk recommends the Whole30 program, a 30-day reset that removes inflammatory foods like sugar, grains, dairy, legumes, and alcohol.

Over the initial 30 days, the diet focuses on:

• Vegetables and fruits
• Lean protein (meat, poultry, seafood, eggs)
• Healthy fats (nuts, seeds, avocados, and olive oil)

“After the 30 days, you can slowly reintroduce foods into your diet to help you determine which foods trigger inflammation,” she counsels. Changing your diet may not eliminate symptoms entirely, but it can reduce flare-ups and improve daily life.

What to Do If You Think You Have Endometriosis

While laparoscopic surgery is often described as the gold standard for confirming endometriosis, an experienced doctor can make a diagnosis of “clinically suspected” endometriosis and consider less invasive forms of treatment depending on your goals (reducing pain, pregnancy, etc.) and comfort level.

Navigating an endo diagnosis is challenging, but being prepared can make a difference:

• Advocate for yourself: If you suspect something is wrong and you’re being told otherwise, seek a second opinion.
• Clearly and consistently track symptoms: Use precise language (i.e., deep ache, sharp, stabbing, throbbing, pressure/heaviness) and note:
  • When symptoms occur (pre-period, during, post-period, mid-cycle)
  • Where they’re felt (pelvis, lower back, hip joint, rectum, bladder)
  • What triggers them (sex, bowel movements, urination)
  • How intense they are (on a scale of 0–10)
• Bring your priorities: Whether your top concern is pain relief, work/school function, or fertility, say so. A good clinician will shape the plan around you.

The Bottom Line

Endometriosis is common, but too often underdetected and undertreated. Pain, fatigue, and mental health issues are all real and valid symptoms. And while diagnosis can take time, getting to the right specialist and building a supportive team can transform your day-to-day life.

If you recognize yourself in this article, the pain, extreme tiredness or unexplained heavy or irregular periods, please know: your pain is real, and you deserve answers and relief.

Dr. McGuirk counsels, “always advocate for yourself. If you suspect something is wrong and you’re being told otherwise, then it’s time to seek a second opinion.” Use the below form to find an endometriosis specialist in your area and get the relief and real care you deserve.