I have been getting really bad stomach pains and diarrhoea for the past 2-3 weeks. I Always get stomach pains literally minutes after I have eaten. I sometimes get them when I'm just thinking of eating something. After the pains I get a sudden urge to go to the toilet, although sometimes I am constipated. I have looked at several explanations online, but still don't seem to have an answer. Most say the pain starts within 1 hour of eating; but the pain I have begins right away, and sometimes during meals.