Hi Lilly
I have suffered from the same problem for over 20 years. Mine, too, occurred immediately after eating. In fact, I could pass corn within 30 minutes of eating it!!!!
When I was 18 I went to a gastroenterologist (g-e) who basically told me it was all in my mind, to go away and eat more yoghurt! Great for an 18 year old's self esteem! Anyway, I battled on for another 5 years or so, finally went to a naturapath who diagnosed Candida, and cut pretty much everything out of my diet. Lost heaps of weight, but problem stayed. Over the next 15 years or so, I battled with the condition, getting worse in times of stress. For the last five or so years it has been at its worst, with the urgency of the diarrhea meaning that I was terrified to be away from a toilet. At times, I have had less than a few seconds to get there, many times not being able to make it. Travelling (particularly car trips) terrified me, as did eating out, going anywhere that I didn't know had a toilet etc! If I had to go anywhere, the first thing I would do would be scout around for a loo! Ring a bell? While I made sure that I didn't eat prior to setting out, there were many times when it hit even without eating. Life was hell, with the condition affecting my relationships, social life, movements, the lot.
I finally bit the bullet at the end of last year and went to a new g-e. I explained my problems and cried when he told me that it wasn't all in my mind and he wouldn't let me go until he had fixed my problem! Thereafter followed a food diary, colonoscopy, numerous blood tests, all of which were normal, except found that I had low fibre in my diet. Increasing this for a 3 week period didn't help. I then had 2 weeks of using Imodium procatively - up until then I had been using them probably every second day, up to 3 or 4 a day to stop attacks once they had started. For that 2 weeks I was to take one immediately before eating lunch (eating lunch usually triggered the attacks). We found in that 2 week period that, while imodium was great to stop attacks once they had started, it didn't prevent them! In fact, in that 2 week period, I had more "accidents" than ever before!
The last time I went back to the g-e, a miracle occurred! He thought that maybe my problem may be caused by bile salts. It works like this - bile salts are produced by the liver, and stored in the gall bladder. When you eat, bile salts are released into your system to assist in the digestion/absorption of fats. In most people, these bile salts are reabsorbed by the body in the small intestines, where they are then stored back in the gall bladder. However, if they are not reabsorbed, they act like a laxative when they hit the large intestine. Maybe my bile salts were not being reabsorbed. This is usually a problem that occurs in people who have had their gall bladder removed - I haven't, but the symptoms all fitted.
The doctor prescribed me a drug called Questran, which was initially released as a cholesterol lowering drug, working by absorbing bile salts (and therefore fats) in the small intestine. After the first day of taking Questran, my life has totaly changed! I can honestly say that my problem has all but gone! No longer to I get the gurgling, uncomfortable pain which, in a matter of seconds turns to the most intense urgency to go to the toilet. No longer am I scared stiff to be more than a minute or so away from the toilet!
There are still a few little things I need to sort out (such as timing of taking the questran, depending on whether I expect to have a large meal at night or at lunch), but apart from that, nothing, zilch, zip!
My advice to you Lilly is don't give up, and don't let your doctor give up on you! Go and see a gastoenterologist, let him rule out any common bowel diseases, and then refuse to stop seeing him until you are fixed. Maybe suggest the bile salt thing to him once everything else has been ruled out - it was certainly my problem!
Good luck - I know exactly how you feel!