It can be tricky to diagnose because it can mask itself as other ailments, including appendicitis, ovarian cysts, diverticulitis or irritable bowel syndrome. Diagnosis is considered uncertain until proven by a surgical procedure known as a laparoscopy. A laparoscopy can usually give doctors information on the location, size and extent of the growths. This helps the doctor and patient make better treatment choices.

Dr. Gililland explains that endometriosis can cause very severe inflammation and scarring in the pelvis, and this could block the fallopian tubes, resulting in intractable pain. "In addition, it can cause tumors in the ovaries and can implant on and in the bowel," he says.

After years of experiencing severe cramping during her menstrual cycle, Lori Hayes-Simperman from Northern California, a patient of Dr. Gililland's, found her symptoms increasing in intensity just about the time that she was trying to conceive her first child. "After 18 months of trying unsuccessfully to conceive, my gynecologist had referred us to Northern California Fertility Medical Clinic in Sacramento," Hayes-Simperman says. "In 1998, we were using the fertility drug Clomid. On the third cycle of using Clomid, we found out the wonderful news: We were pregnant!"

Subsequently, Hayes-Simperman endured a six-hour surgery where she was diagnosed with stage four endometriosis. She was told that it was truly a miracle that she was able to conceive with the extent of the disease. "Now I am pain-free, living a normal life with the ups and downs of trying to conceive again with fertility drugs," she says.

Want to see more?

• When Life Is a Pain: The Facts on Endometriosis
• Physician or Friend: Can Your Doctor Be Both?
• At Your Cervix: A Lifetime of Cervical Health
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