Aug. 7, 2009 -- In the movies and on television, everybody seems to love having sex, but in real life sexual intercourse is an unbearable experience for many women.
For Veasley, 33, of Providence, R.I., the unbearable vaginal pain extended beyond sex to everyday activities like walking. Even light contact from blue jeans could be too agonizing to bear.
"Riding a bike, sitting for long periods and something as light as touching the area with a Q-tip will send women kind of flying off the exam table," she told ABC News' Dr. Timothy Johnson.
"The best way to describe it is having sandpaper rubbed on an open wound," Fontaine said.
But all the women said what's almost harder than the physical pain is the emotional toll of suffering from such a mysterious condition without a clear diagnosis.
Fontaine, 25, of New York City said she went to 15 different doctors in a desperate search for answers. Some of those doctors said it was psychological.
"Having doctors tell you there's nothing wrong even though you know there's something wrong, it's beyond frustrating and it's heartbreaking. I was either on medicine, in treatment for something that I didn't have or I was being told that 'it's all in your head,'" she told ABC News.
Veasley said she also struggled to find a diagnosis. Remarkably, five years into her relationship with her college sweetheart, Melvin, they still had never had sexual intercourse because it was just too painful for her. But it didn't stop them from getting married.
The couple said they found other ways to be sexually intimate, but the desperate search for a diagnosis for this inexplicable pain can either pull a couple closer together or tear them apart.
Fontaine and her husband, Afsheen, said their marriage was seriously strained by her mysterious sexual pain.
"All the results are coming back negative and after I would tell him and he would automatically assume it was himm you know, I am not attracted to him anymore," Fontaine said.
Former Sufferer: Sexual Pain Is 'Kind of an Assault on Your Ego as a Woman'
The men aren't the only ones doubting themselves.
"Part of what makes you a woman is having female sexual organs and when they're not working properly, it's kind of an assault on your ego as a woman," said Nugent, 34, of Tacoma Park, Md.
Her pain ended up being an assault on her marriage as well as her ego, she said.
In fact, Nugent said that her pain was largely to blame for the failure of her first marriage.
"It certainly added a tremendous amount of stress to the marriage," she said. "Handling a serious illness or a chronic pain condition is difficult, no matter what, but handling a chronic pain condition when nobody can tell you what it is you have or how to treat it is just, you know, beyond the pale."
Luckily, Nugent was able to find a doctor who could treat her mystifying pain.
Dr. Andrew Goldstein, who runs the Center for Vulvovaginal Disorders in Washington, D.C., and is a pioneer in the new field of sexual pain disorders, said there are usually real physical reasons why sex is so painful for some women.
"A lot of these problems are actually relatively easy to treat if you know how to evaluate them," said Goldstein, whose groundbreaking medical textbook, "Female Sexual Pain Disorders," was published earlier this year.
These problems are by no means rare. Goldstein said an astounding 20 million American women will suffer from sexual pain disorders at some point in their lives. Despite this prevalence, help for these disorders is still hard to find.
"I would say that probably only about 30 to 40 physicians in the United States really have extensive training in female sexual pain," Goldstein said.
This may explain the fact that the average woman with sex pain sees seven different doctors before she gets a diagnosis.
So what are the main causes of sex pain?
Causes of Sex Pain Vary But Are Easily Treated in Most Cases
Perhaps ironically, the number one cause is birth control pills, Goldstein said. Birth control pills lower two hormones in the body -- estrogen and testosterone -- and that can lead to dryness and thinness in the vagina, which can lead to pain. For some women, that pain can be relieved by a simple adjustment to their birth control.
The second leading cause of sex pain is tight pelvic muscles, Goldstein said. In Fontaine's case, she received treatment with physical therapist Amy Stein, who she said helped her by stretching and strengthening her tight pelvic muscles.
"I tell patients that it's similar to neck pain, a neck spasm, but it's in the pelvic floor area and what we have to do is go in and lengthen the muscles," said Stein, who is one of a handful of physical therapists who specialize in sex pain and has written a book on the topic, "Heal Pelvic Pain."
Some doctors also use Botox injections to relax the pelvic muscles, allowing physical therapists to stretch them more easily.
According to Goldstein, the third leading cause of sex pain is an overabundance of nerve endings at the opening of the vagina. Though it's small, this postage stamp-sized area can generate a lot of pain, he said.
All three women -- Fontaine, Nugent and Veasley -- had this nerve problem. Fontaine said she found relief with some hormonal cream that soothed her nerve endings.
"I am able to have intercourse now, finally, and it's not painful," she said.
Nugent and Veasley both had minor procedures to remove the nerve endings. This simple, out-patient surgery -- known as a vestibulecyomy -- cures the problem in 90 percent of the women who have it.
Other causes of sex pain include endometriosis and skin diseases, Goldstein said.
Women Must 'Become Their Own Advocates' in Fight Against Sex Pain, Says Former Sufferer
Nugent said she is now happily remarried and, thanks to the surgery, was able to conceive and give birth this spring to a baby boy named James.
"It's important to get treatment and to talk to your doctor about it, but if your doctor doesn't believe you have a problem, then it's important to talk to someone who does understand the problem," she said.
Like Nugent, Veasley said she is deeply grateful that she found an answer to her problems.
"I feel fortunate to have found an answer for my pain, espcially because so many women do not," she said. "Those seven agonizing years compelled me to use my experience to help other women in pain."
She now works as the associate executive director for the National Vulvodynia Association, an organization created to improve the lives of individuals affected by vulvodynia, a spectrum of chronic vulvar pain disorders. She said she has made educating other women and medical professionals about vulvar pain her vocation.
"It is so important for women to educate themselves, become their own advocates and most importantly, to never give up hope," she said.
After years without sexual intercourse together, Veasley said she and her husband have been able to enjoy pain-free sex for more than eight years now, and the living proof of that is their two daughters, appropriately named Grace and Faith.
To find a doctor in your area who specializes in the treatment of pelvic pain, click here.
For information on physical therapy for sexual pain disorders, click here.