The medical team encircled Mackenzie Hild’s bed, their somber expressions reflecting the gravity of the news they were about to impart to the Harvard sophomore and her mother, newly arrived from California.

“We’ve done all these tests, and they’re all normal,” Hild recalls one doctor at the renowned Boston hospital telling them. To treat Hild’s life-threatening weight loss, which the 19-year-old claimed was the result of searing abdominal pain triggered by eating, doctors were sending her to an inpatient center specializing in eating disorders.

Medical Mysteries is a monthly column recounting the diagnosis of a puzzling medical case. (Cam Cottrill for The Washington Post)

Hild, who at 5-foot-3 then weighed 75 pounds, remembers weeping as she tried to explain that she didn’t have anorexia. She desperately wanted to eat, she insisted, but couldn’t.

“I didn’t know how to convince them this is not in my head,” recalled Hild of the September 2010 encounter. “And the more I tried to convince them, the crazier I sounded.”

For the next five years, Hild would repeatedly confront the erroneous belief that her pain, which began soon after eating or drinking and lasted about four hours, was the result of stress, perfectionism, attention-seeking or just plain hunger. “There were times I wasn’t sure myself,” she said.

Exhaustive testing and treatment at several of the nation’s most prominent hospitals failed to uncover a physical explanation. Removing her gallbladder didn’t help. For five years — while attending college, during two summers working on Navajo reservations and a 10-month fellowship in South Africa — Hild was kept alive by a feeding tube. She tried to avoid focusing on what seemed a near-impossibility: an explanation for the relentless pain and a treatment that would vanquish it.

Last year, an extraordinary confluence of events would make both a reality.

The catalyst was a chance meeting between Hild’s parents and a medical school professor on a remote hiking trail in California’s Sierra Nevada.

Intrigued by Hild’s case, he asked a fourth-year medical student to review it. The tenacious student zeroed in on an overlooked clue buried in Hild’s voluminous file, then reached out to a surgeon in Chicago. In March 2015, the surgeon performed the 2½ -hour operation that restored Hild’s life.

Mackenzie Hild suffered with excruciating abdominal pain for 5 years. Hild’s weight plummeted to 75 pounds and she had to be fed through a tube before doctors reached the right diagnosis. (The Washington Post)

Drug reaction?

Since childhood, Hild, now 26 and a second-year medical student at the University of Washington in Seattle, wanted to work in Africa as a doctor. In the summer of 2009 before entering Harvard, Hild spent three months at a rural clinic in Uganda. Within days of her arrival, her stomach began to hurt after she ate. Hild, who lost 15 pounds, suspected that an antimalarial drug was responsible.

Back home in rural Nevada City, Calif., and off the drug, the pain lessened but did not disappear. Because of Hild’s travel history, she was tested for parasites. Tests were negative and she regained the lost weight. She spent the following summer in Rwanda working with HIV patients as part of the medical aid group Partners in Health.

When she got off the plane in August 2010, Hild’s family was shocked. Always thin, she had lost 35 pounds — more than a third of her body weight — a consequence of stomach pain that had worsened dramatically. Doctors again tested her for numerous tropical diseases and she underwent a thorough work-up for HIV as well as serious digestive disorders, including Crohn’s disease. All tests were negative.

Mackenzie Hild, 26, a medical student who spent this past summer in Kenya, said her ordeal has given her “a totally different perspective on medicine and a new level of empathy.” (Courtesy of Mackenzie Hild)

At school, her health worsened. A few weeks into her sophomore year, she went to the student health center. “They said, ‘You’re too skinny, we’re putting you in an ambulance,” Hild said, recalling her admission to the Boston hospital.

After her confrontation with the medical team, Hild spent nearly a month in a unit for people with eating disorders. Despite intense pain, she managed to gain nearly 20 pounds. She took a medical leave and spent the year at home, seeing doctors in a futile attempt to determine the cause of the stabbing pain right below her diaphragm, which was accompanied by bouts of nausea.

In the spring of 2011, the pain was so debilitating that Hild opted for a feeding tube that snaked up her nose, down her throat, through her stomach and into her small intestine. Doctors hoped it would allow her gut to rest and enable her to resume eating.

When her weight reached 105 pounds, doctors approved her return to Harvard. “I loved college, and I was desperate to go back,” Hild said. “But there was still no answer. And I was getting 100 percent of my nutrition delivered through my nose.”

After months of tube feeding, her Boston gastroenterologist, who had ruled out anorexia, grew concerned that her stomach might start to atrophy. He urged her to consume small amounts, such as a few sips of a high-calorie nutritional drink, several times a week.

“I would eat at 8 p.m. and for the next four hours would lie on my bed in a fetal position,” she recalled. The feeding tube also caused repeated sinus infections and frequent hoarseness.

Hild was determined not to let her condition rule her life. She carried a full course load, did volunteer work with the homeless and had supportive friends who included her in their plans. In a nod to her major, Hild approached not eating as “an anthropology experiment.”

“I got used to explaining it,” she said, adding that “it was amazing how much of college revolves around eating.”

In May 2012, San Francisco surgeons replaced her feeding tube with a less conspicuous one implanted in her abdomen. They also removed Hild’s gallbladder. The pain was undiminished.

Hild pictured with adults and children in Kenya this past summer. Despite her illness, Hild managed to graduate from Harvard, spend two summers working on Indian reservations and volunteered in South Africa. (Courtesy of Mackenzie Hild)

Hild spent the next two summers doing medical work on reservations in Arizona and New Mexico. She saw a world-famous GI expert at a major medical center in the Midwest and spent a week there undergoing a regimen to speed digestion; it didn’t help. “I had high hopes that this would be the answer,” she recalled. She began taking a new drug that enabled her to better manage the pain and nausea. “I began to think that maybe someday I’d get my stomach back.”

Hild had always planned to take a year off before medical school and was eager to return to Africa. “I sat down with my doctors [in Boston] and said, ‘Which countries would you let me go to?’ They looked at me like I was crazy and then said, ‘Okay, South Africa.’ ” Her gastroenterologist helped arrange care for her with a specialist he knew in Cape Town. She departed a few days after her May 2014 graduation to work on a maternal mortality project in the impoverished townships.

A few months later, the serendipitous meeting that changed her life would take place more than 10,000 miles away.

Extraordinary coincidence

In August, Hild’s parents struck up a conversation with a fellow hiker on a backcountry trail in the Sierras. He turned out to be a doctor at the University of California at San Francisco who specializes in advocating for patients with complex cases. The Hilds mentioned Mackenzie, and the doctor asked if he and a colleague might contact her. They were teaching a course on medical advocacy, and her case sounded promising.

Over the next few months, the doctors, along with student Jessica Gould, held a series of Skype chats with Hild.

“I was flabbergasted that Mackenzie was so accomplished and so graceful” despite her illness, recalled Gould, 29, now a family medicine resident at the University of California at Davis. “And I remember feeling completely and totally intimidated. She had been seen by some of the top experts at some of the top hospitals in the country. What could I as a fourth-year medical student possibly offer?”

With her professors, Gould devised a series of questions that would guide the inquiry. She then spent 50 hours chasing down leads, gathering thousands of pages of records from several hospitals and scouring medical databases.

Early on, Gould typed “postprandial abdominal pain” (pain after eating) into a medical search engine. One of the hits was a condition called MALS — median arcuate ligament syndrome. First described a century ago, MALS occurs when a band of connective tissue called the median arcuate ligament, which extends from the base of the diaphragm and crosses over the aorta, compresses the celiac artery, which supplies blood to the stomach and other organs.

While such compression is common — between 10 and 20 percent of the population has this anatomical variation — only 1 percent develop severe abdominal pain. A leading theory is that compression restricts normal blood flow to the digestive organs. Rapid weight loss or illness appears to be a trigger; MALS overwhelmingly affects females, sometimes young children. It is a diagnosis of exclusion based on symptoms and imaging, made after other disorders, including anorexia, have been ruled out.

Surgery to relieve the compression alleviates pain in 70 percent of cases, experts say, but there is no definitive way to tell who will benefit. Some doctors remain skeptical of the diagnosis.

Gould had never heard of MALS, but was struck by the similarities to Hild’s symptoms. “I thought, ‘Oh, my gosh, this is what she has.’ ” She soon discovered that MALS had been ruled out years earlier.

A few months later, after hitting multiple dead ends, Gould, at a professor’s suggestion, decided to take a second look. She emailed three prominent experts asking about testing required to check for MALS. The only response was from Christopher Skelly, chief of vascular surgery at the University of Chicago Medical Center.

Skelly agreed to review Hild’s case. “It did look like she had MALS,” he said, after examining images from earlier tests that appeared to contradict the written report ruling it out.

During a January 2015 phone call, Skelly told Hild that he thought she had MALS and that surgery might help. She would need to meet with him and undergo additional testing as well as a psychiatric evaluation Skelly requires of all patients before surgery. And, he cautioned, the operation might not reduce her pain.

Skelly, who heads Chicago’s MALS program and has operated on more than 200 patients, said he was struck by Hild’s resilience. “The psychological effects of dealing with chronic abdominal pain are really difficult,” he said. “Mackenzie’s ability to adapt and cope was amazing.”

Hild was euphoric at the prospect of a diagnosis after six years of misery — and five years on a feeding tube. “I made this crazy, spontaneous decision to fly to Chicago as soon as he could see me,” she said. Four weeks later, testing confirmed Skelly’s suspicion. An earlier CT scan had been performed incorrectly, producing a false negative result.

“My first reaction was complete disbelief,” Hild recalled. “I couldn’t believe so many doctors had missed this. And I was just so happy to have an answer.”

She underwent surgery March 18. The next day, Hild ate a spoonful of hospital scrambled eggs — and waited. When she felt no pain, she burst into tears. Hild battled weeks of postoperative nausea, which dissipated as her stomach grew accustomed to eating. Her pain has not returned.

Hild spent the summer in Kenya working on a clinical trial for the prevention of tuberculosis. “I even gained two pounds,” she said. She believes her ordeal has given her “a totally different perspective on medicine and a new level of empathy I don’t think I could have gotten any other way.”

Gould, whom Hild calls her “hero,” said she is still surprised that her role as a mere med student was so pivotal. “I think there’s something to be said for an outside eye,” she said.

Submit your solved medical mystery to sandra.boodman@washpost.com. No unsolved cases, please. Read previous mysteries at wapo.st/medicalmysteries.