Hi. Thanks for your query. If the pain is initiated with certain foods this is an allergy and intestines respond by spasmodic contraction to get the thing removed out of the system. Colonoscopy may be absolutely normal in such cases. It is possible that you are suffering from Irritable Bowel Syndrome. I would advise a Contrast enhanced CT scan in all such cases to rule out any organic problem like appendicitis, lymph node enlargement, small bowel problems like thickening or obstruction due to a particular cause. The primary treatment is avoidance of all such food and beverages which enhance this problem. If the stress is a contributory factor, it has to be treated by psychotherpy , avoiding activities causing stress and anxiety and if required , some medicines ,