I found this on imdb.com in the current news section:
http://www.imdb.com/PeopleNews/#3 American superstar Britney Spears has fans fearing for her health following a mystery visit to a Californian hospital on Thursday. The pop beauty, 22, arrived with mum Lynne for an hour-long appointment at the Centinela Hospital in Los Angeles. The following day, the blonde multi-millionairess - spotted for the first time since her sham 55-hour Las Vegas marriage to Jason Alexander - visited the Parkside Medical Centre in Santa Monica, California, for an 8.30am appointment. Again the star was accompanied by Lynne, who is reportedly worried about her eldest daughter since her bizarre marriage and annulment to childhood pal Alexander. A Parkside source says, "Britney's appearance here was the talk of the center. She looked very downcast and subdued."
I don't how reliable this story is, but imdb.com is a reputable site with mostly accurate information...