(Health.com) -- Sarah Cooper was a new mom in her mid-20s, busily juggling her family and a career as an electrical engineer, when everything came to a halt.
She lost all her energy. She developed acne. And she began experiencing gastrointestinal problems: bloating, diarrhea, cramping, constipation. Her doctors, thinking something must be missing from her diet, put her on various vitamins, none of which helped.
"It was all I could do to go to work," she says.