The fact that Leaky Gut is different and not considered an IBS issue is partly why I wonder if it's truly IBS that I have. Either way, whatever I have, my goal is to "fix" it.
I do adhere to the EFI diet (most of the time-I'm only human and enjoy a glass of wine or some cheese now and again) and also try to avoid wheat. And after recently coming across FODMAP's, I consulted a Dietitian (I'm done with my family doctor and GI) who was surprised with what/how much I already knew and said I'm already doing everything with my diet that he would recommend anyway and just keep doing what I'm already doing.
I just think (with my body anyway) that there's a definite cause and effect with my digestive enzymes and bile acids whether its the gallbladder, pancreas or liver. This is what I'm going to experiment with as you are with the melatonin. I'm very interested to hear how you make out as one thing I've noticed over the years is that I'm much more stable after a good nights sleep (which has been hard to come by for me with my work shift and 3 young children). To hear you say "clinical evidence shows that 3 mg of melatonin taken at bed time can reduce urgency and pain. I have had pain with my IBS-D for decades. Recently I tried melatonin. After about 10 days the pain and urgency were significantly decreased. I am rather amazed at how well it works for me. Some time soon I will post an overview of the research on melatonin and IBS."