2008-08-01 09:04:02 - Cher's joy over her upcoming wedding to Tim Medvetz is being clouded by her son Elijah Blue Allman's illness.

Cher's upcoming wedding plans have been affected by her son's mystery illness. The 'Believe' singer - who was set to marry Tim Medvetz by the end of the year - reportedly can't stop worrying about Elijah Blue Allman's

unknown condition. A source said: "This should be the best time of Cher's life. She is enjoying a love affair with daredevil adventurer Tim, and they plan to get married by the end of the year. But poor Elijah keeps playing on her mind." Elijah, 32, began exhibiting strange symptoms since returning from New Delhi, India, two years ago, and doctors have not been able to diagnose his illness. The source added to National Enquirer magazine: "At first he believed he got a bad case of food poisoning in India. As soon as he got back to Los Angeles, he began complaining of a constantly upset stomach and flu-like symptoms. Chronic fatigue, bowel problems, headaches and a host of intestinal troubles soon followed. "In the past two years, Elijah has had over 40 colonics, along with other holistic treatments. But that hasn't helped either." Elijah is now seeking treatment at specialist clinic Leonardis Klinik in Germany.