You have ulcerative colitis. You can't have tomatoes, lettuce - it's like razor blades and you will get diarrea. I've have same symptoms. Stay away from nuts and popcorn. Stay away from acidic foods too OJ, chocolate, coffee. Eat bland food. Nothing spicy. Stay away from apple juice. Try to stay away from processed food - cook from scratch.
You need to heal and it will takes months and then slowly eat these things again but only once in a while. I couldn't eat a salad for 2 years without having bad side affects. I used to live in the bathroom so I know the feeling. Be patient and keep a food journal and watch for triggers. Stay away from high fiber diets - just have 2 tablespoons of flaxseed everyday and Put In a coffee grinder - it's has great health properties Good luckView Thread