Ashley Pettis started to have trouble concentrating at the end of spring semester in 2013 at Lancaster Bible College, and soon began to feel sluggish and achy.

Exhausted by the end of the summer, she was found to have mononucleosis. But later, she still felt sick, and went that fall to Haverford Wellness Center in the Montgomery County town of Harleysville, seeking answers.

Clinicians there said she had late-stage Lyme disease, a chronic form of the tick-borne illness that is diagnosed in an estimated 300,000 Americans a year.

The treatment they administered was controversial: five months of heavy-duty oral and intravenous antibiotics costing tens of thousands of dollars that her insurance would not cover. In June 2014, suffering severe abdominal pain, she landed in the Grand View Hospital emergency room, where physicians removed her gallbladder and delivered a shocker:

Pettis did not have Lyme disease at all.

Now Pettis, 22, and her father are suing the Haverford Wellness Center and Domenick Braccia, the self-described "Lyme literate" physician who treated her there. They allege that Braccia was negligent and reckless, administering an unproven and harmful treatment.

Braccia did not respond to requests for comment. But in court papers, his attorney, Kevin H. Wright, disputed the allegations, contending that the suit fails to identify any facts indicating negligence or recklessness.

One fact not in dispute: Medicine has a long way to go in figuring out the riddle of Lyme disease, and its diagnosis and treatment.

The lab tests that doctors use to help diagnose the potentially debilitating bacterial illness are not reliable. Among those who have the disease, a minority can experience symptoms long after the standard treatment with several weeks of antibiotics.

That has led some physicians to recommend extended courses of antibiotics, on the theory that some of the bacteria survive initial treatment. Some studies find this can happen in animals; evidence in humans is limited.

Some patients on long-term antibiotics have reported declines in pain and fatigue, though there is debate over how these results should be interpreted. The use of the drugs in such patients is controversial.

Brian Fallon, director of Lyme and tick-borne disease research at Columbia University Medical Center, said long-term antibiotics should be an option for certain patients.

"Given the fact that our current Lyme tests are not 100 percent accurate, there needs to be flexibility allowed to the clinician," Fallon said.

But Paul Auwaerter, an infectious diseases specialist at the Johns Hopkins University School of Medicine, said the medicines are not worth the risk.

Some of the antibiotics are delivered intravenously, raising the risk of blood clots and other complications, Auwaerter said. Repeated courses of antibiotics can interfere with the body's natural bacteria. And one of the drugs, ceftriaxone, has been linked to gallbladder problems such as Pettis experienced.

Pettis told the Haverford Wellness Center she had been treated for possible Lyme disease once before, in February 2013, with the standard 21-day course of antibiotics.

Yet a blood test before that treatment came back negative for Lyme. And a test in November 2013 ordered by Braccia's office came back negative again. Citing her symptoms, he told her she had the disease, and started her on multiple antibiotics, according to the lawsuit.

Records provided by Charles P. Hehmeyer, her attorney, indicate that she took the drugs for five months, often several at a time. Some were given intravenously at Braccia's clinic, requiring a daily drive of up to two hours each way from her apartment in Lancaster.

She grew sicker, experiencing nausea and eventually seizures, she said. She lost weight and grew so weak she could not make the drive to the clinic. At the doctor's urging, she moved into a house near the clinic with other long-term patients, paying rent of $250 per month, she said. It was owned by a family member of Kim Braccia, the doctor's wife and office manager, according to the lawsuit.

Whenever Pettis tried to ask about other treatment options, she was rebuffed, she said in an interview. At one point she had trouble breathing but was discouraged from going to an emergency room, she said.

"As soon as you start raising questions or asking to seek other medical advice, they become very abrupt with you," Pettis said.

She finally went to the Grand View emergency room in Sellersville. In addition to removing her gallbladder, doctors there urged her to stop the antibiotics.

Pettis agreed, moved out of the house where she had been living with other patients, and eventually recovered. The lawsuit seeks the recovery of more than $30,000 in medical expenses as well as punitive damages.

Pettis says her health is now good. She recently got married. The main goal of her lawsuit, she said, was to see that other patients would not go through the same experience.

"I was on so many medications, I couldn't even think clearly," she said. "I just would hate to see that happen to people and not being able to get out in time."