Hi. Thanks for your query. Noted your history of stomach cramps as if you need to go for motion but nothing comes out. This is called tenesmus. But then you throw up, all the foods come out and followed by the acid. This may be due to bad foods that you might have taken. But if the problem is of a long standing nature, you need a proper clinical evaluation and treatment. I would advise you to consult your Doctor, get stool, urine and blood tested as well as ultrasound to start with and CT scan of the whole abdomen if positive findings are there. Colonoscopy and biopsy helps to confirm or rule out many a diseases and hence is a must in such cases. I hope this answers your query and helps you in early diagnosis and proper treatment.