Her Doctor Said Her Illness Was All in Her Head. This Scientist Was Determined to Find the Truth.

Taped above a tidy wooden desk in the corner of her bedroom, right at eye level, is a piece of paper that Marlena Fejzo has saved for 24 years.

It’s a portrait of Dr. Fejzo at age 31 during the worst ordeal of her life. Her face and body are drawn in the gaunt greens and yellows of illness; her hollowed cheeks are marked with tears. The colored pencil drawing, made by her sister in 1999, is the only image she has held on to from that time. The few photos her mother took “were too horrible” to keep, said Dr. Fejzo, now 55.

A little nausea and vomiting in pregnancy were normal, she knew. But she experienced weeks of debilitating illness when she was pregnant with her son, and when expecting her second child, Dr. Fejzo was so ill that she couldn’t move without vomiting.

She couldn’t go to work or care for her little boy, or swallow so much as a teaspoon of water, let alone a bite of toast or a prenatal vitamin. Her empty gastrointestinal tract would spasm so violently and for so long that she couldn’t breathe.

“Every living moment was torture,” she said.

For at least a month, Dr. Fejzo couldn’t keep down any food or drink, and she received fluids through an IV. Her weight dropped to 90 pounds from an already slight 105, after which she grew too weak to stand on a scale.

“I was starving,” she said, “and the doctor just kept trying higher doses of drugs and different drugs, and nothing helped.”