Pelvic Pain in Women: Understanding Endometriosis and Interstitial Cystitis

For many women, pelvic pain isn’t just a bad day-it’s a daily battle. It shows up when you’re trying to sleep, during sex, while peeing, or even sitting at your desk. Two conditions, endometriosis and interstitial cystitis, are often behind this suffering-and they’re frequently mistaken for each other. Worse, many women wait years before getting the right diagnosis. If you’ve been told it’s ‘just stress’ or ‘a UTI that won’t go away,’ you’re not alone. This isn’t normal. And it doesn’t have to be this hard.

What Endometriosis Really Feels Like

Endometriosis happens when tissue similar to the lining of your uterus grows outside it-on your ovaries, fallopian tubes, bowel, or even your bladder. It doesn’t just cause cramps. It causes deep, burning, stabbing pain that often gets worse around your period. About 92% of women with endometriosis report cyclical pain tied to their menstrual cycle. Some describe it as feeling like their insides are being torn apart. Others say it feels like a constant pressure, especially during bowel movements or sex.

The pain doesn’t always match the severity of the disease. A woman with stage I endometriosis can have worse pain than someone with stage IV. That’s why relying on pain levels alone to judge the condition doesn’t work. The only way to confirm endometriosis is through laparoscopic surgery, where a surgeon removes tissue samples for testing. This isn’t a simple procedure-it costs between $5,000 and $15,000 in the U.S., requires general anesthesia, and takes 2 to 4 weeks to recover from. But without it, you’re flying blind.

Bladder endometriosis affects 1 to 12% of people with the condition. When it happens, you might notice blood in your urine during your period, pain when your bladder fills, or sudden urges to pee. These symptoms look exactly like interstitial cystitis-which is why so many women get misdiagnosed.

What Interstitial Cystitis Actually Is

Interstitial cystitis (IC), also called painful bladder syndrome, is a chronic condition where the bladder wall becomes inflamed, leading to pain, pressure, and urinary urgency. Unlike a urinary tract infection, there’s no bacteria to kill. No antibiotics will help. The bladder becomes hypersensitive, and even small amounts of urine trigger sharp pain. Most women with IC feel the need to pee more than 7 times a day-and sometimes up to 60 times.

The pain doesn’t follow your cycle like endometriosis. It’s usually constant, though it can flare up around your period. About 45% of IC patients say their symptoms get worse during menstruation, but they don’t disappear afterward. A key sign is pain when your bladder fills, and relief after you empty it. Many women describe it as a burning, aching, or pressure sensation deep in the pelvis.

Diagnosing IC is tricky. There’s no blood test, no scan, no single marker. Doctors have to rule out everything else first-UTIs, bladder cancer, sexually transmitted infections, kidney stones. The process can take months. A cystoscopy (a scope inserted into the bladder) is often used, and sometimes a potassium sensitivity test (PST), which checks how your bladder reacts to a potassium solution. If it hurts badly, it’s a sign of IC. But even the PST has a 20% false negative rate. That means one in five people with IC are told they’re fine.

Why These Two Conditions Are So Often Confused

Endometriosis and IC share nearly every symptom: pelvic pain, painful urination, frequent urination, pain during sex, and discomfort during bowel movements. In fact, a landmark 2011 study of 178 women with chronic pelvic pain found that 65% had both conditions at the same time. That’s not coincidence. It’s a pattern.

Many doctors still treat them as separate problems. They diagnose one, treat it, and if the pain comes back, they assume the first diagnosis was wrong. But what if both are present? That’s what’s happening to so many women. Dr. Tamer Seckin, a leading endometriosis specialist, says: ‘It is not possible to confirm interstitial cystitis without first excluding endometriosis.’

One major clue? Blood in the urine. If you see red or pink in your urine during your period, it’s far more likely to be bladder endometriosis than IC. Pure IC rarely causes bleeding. Another clue? Pain that worsens predictably with your cycle. If your pain spikes right before your period and fades after, endometriosis is likely playing a role.

And here’s the hard truth: up to 80% of women diagnosed with IC actually have undiagnosed endometriosis, according to Dr. Robert Moldwin, a urology professor. That means thousands of women are being treated for the wrong thing-while the real cause keeps growing.

What Happens When You’re Misdiagnosed

Getting the wrong diagnosis doesn’t just waste time-it causes real harm. Women with IC are often prescribed antibiotics for supposed ‘recurrent UTIs.’ One survey found that 41% of women with endometriosis were given antibiotics an average of 5.3 times before their real diagnosis. Antibiotics don’t fix endometriosis. They just delay the truth.

And then there’s the emotional toll. A 2023 survey of 850 IC patients found that 76% were told their pain was ‘all in their head.’ One Reddit user, u/PelvicPainWarrior, waited nine years for a correct diagnosis. She was told she had IC, took medications that made her sick, and only found relief after a laparoscopy revealed stage IV endometriosis on her bladder wall. After surgery, her urinary symptoms improved by 80%.

Pelvic floor dysfunction is another hidden player. Research shows that 92% of women with either condition have tight, painful pelvic floor muscles. This isn’t just a side effect-it’s part of the problem. Tight muscles can mimic bladder pain, worsen urinary urgency, and make sex unbearable. Physical therapy focused on pelvic floor relaxation can help-but only if the root cause is identified first.

How to Get the Right Diagnosis

If you’ve had pelvic pain for more than six months, it’s time to push for a full evaluation. Here’s what to ask for:

• A detailed medical history and voiding diary (track how often you pee, how much, and when it hurts)
• A pelvic exam by a specialist trained in endometriosis
• Urine tests to rule out infection
• A cystoscopy with biopsy if bladder symptoms are present
• Laparoscopic surgery with deep excision if endometriosis is suspected-even if imaging looks normal
• A referral to a urogynecologist or endometriosis specialist

Don’t accept a diagnosis of IC without ruling out endometriosis. And don’t let a normal ultrasound or MRI fool you-endometriosis doesn’t always show up on scans. Only surgery can confirm it.

In 2024, the Endometriosis Foundation updated its surgical guidelines to require bladder evaluation during every excision surgery. That’s a step forward. But most doctors still don’t follow this. You may need to be your own advocate.

Treatment: What Actually Works

Treatment depends on what’s causing your pain. If it’s endometriosis, excision surgery is the most effective option. Removing the tissue-especially from the bladder-can resolve urinary symptoms in up to 80% of cases. Hormonal therapies like birth control or GnRH agonists may help manage symptoms, but they don’t remove the disease.

For IC, treatments include bladder instillations (medication placed directly into the bladder), dietary changes (avoiding caffeine, alcohol, acidic foods), pelvic floor physical therapy, and medications like pentosan polysulfate sodium (Elmiron). But here’s the catch: Elmiron has been linked to retinal damage in up to 23% of long-term users. It’s not a safe long-term fix.

The best outcomes come when both conditions are treated together. A 2022 review of 342 patients found that 63% saw major improvement when they got surgery for endometriosis AND pelvic floor therapy for IC. That’s the key: dual treatment, not either/or.

Where to Find Help

Finding the right doctor makes all the difference. Look for specialists who do deep excision surgery for endometriosis-only about 15% of U.S. OB/GYNs have this training. For IC, seek out urogynecologists. There are only about 350 board-certified ones in the country.

Support groups matter too. The Endometriosis Foundation has 12 city-based support networks. The Interstitial Cystitis Network has over 15,000 members online. Talking to others who’ve been there can help you feel less alone-and give you the courage to push for better care.

The Future Is Changing

In February 2024, the NIH gave $4.2 million to the University of Michigan to find biomarkers that can tell endometriosis and IC apart with a simple urine test. That’s huge. If they succeed, we could cut years off diagnosis times.

Experts like Dr. Hugh Taylor at Yale predict that by 2030, pelvic pain centers that combine gynecology, urology, and physical therapy will be the standard-not the exception. Until then, you might have to fight for your diagnosis. But you’re not wrong. Your pain is real. And you deserve care that sees the whole picture, not just one symptom.