Ephedra and other stimulants in herbal supplements are blamed for a Maryland woman's case of bloody diarrhea. A military doctor at Andrews Air Force Base treated the 26-year-old woman's ischemic colitis, a disease primarily diagnosed in elderly people when too little blood flows through the walls of the colon. Dr. Courtney Ryan reported that the condition disappeared shortly after the woman stopped taking the herbal supplements.

Dr. Ryan reports that the woman was not taking any prescription medications at the time of her illness but had been taking two different herbal supplements during the previous three months. The supplements contained Ma Huang, also known as ephedra, and other stimulants. The constriction of blood vessels caused by the stimulants is blamed for the colitis.

Ma Huang is a popular herbal supplement in China. It is popular in the United States as a stimulant marketed for increasing metabolism and energy. In recent years, ephedra and ephedrine, its active ingredient, have been linked to increased risks of heart attacks, seizures and strokes, all due to an ephedra-induced increase in blood pressure. However, this is the first case of colitis associated with the stimulants.

Critics say Dr. Ryan's case study is unreliable. They wonder why cases of colitis have never been reported before despite the heavy usage of ephedra-containing supplements.