Dumping Syndrome when no surgery

I am a 25 year old female who has been experiencing symptoms identical to those found in dumping syndrome (nausea, cramping, weakness, warmth, diarrhea--especially after eating or drinking sweets) since I was about 13.  All doctors I have talked to are stumped.  I have never had any type of surgery, nor have I had ulcers or any other stomach problem.  I am wondering if I am the only person who experiences this dumping syndrome without having undergone a serious stomach alteration.  I have altered my diet to prevent these episodes, but I occassionally still experience these painful episodes.

Please, any help would be appreciated.

[ozark]

have you been worked up for lactose intolerance or food allergies? diabetes?

[cornin]

I have been worked up for diabetes and found to be negative.  Also, if I drink milk or eat other dairy products I have no problem...only really sweet things like soda and candybars seem to bother me.

[CHADDY]

maybe caffeine could be the culprit

[chichi1]

A related discussion, dumping without surgery was started.