From the UK CAA website..
(sorry about the odd formatting). Original is here...
http://www.caa.co.uk/WorkArea/Downlo...?id=4294973798
Bariatric surgery promotes weight loss by altering the anatomy of the digestive system and limiting
the amount of food that can be eaten/digested e.g. gastric bypass or gastric banding. It is a major
procedure that is usually considered as an option if an individual’s BMI is 40 or more, or between 35
and 40 if other risk factors that could be improved by a reduction in weight are present. Other
criteria also need to be fulfilled and this option should be discussed with your GP/specialist. If it is
deemed an acceptable for treatment for you and you decide to proceed, you must notify your AME
as you will be assessed as ‘unfit’ for a period of up to 3 months post surgery which will be
dependent upon the type of procedure performed and your recovery. Endoscopic procedures will
significantly reduce this period. Detailed reports will be required to confirm that you have made a full
recovery from the procedure, are not experiencing any incapacitating side-effects, and a final
assessment with your AME will be required before you can be assessed as ‘fit’ again. Any other
treatment or procedure that you might be considering must be discussed with your AME.