Harry, I also get canker sores from bananas and sometimes chocolate if it’s very strong! For me, I think it’s the potassium in the bananas, especially if they are not completely ripe. I also get them from walnuts. I never thought there was a connection between that and the Crohn’s but who knows? And yes, it is good to know we’re not alone, as it can be a very lonely disease due the nature of the symptoms.