Hi and welcome to the forum! I am glad that I can help you.
You want to know what the cause of the abdominal pain that you experience.
Abdominal pain may appear due to menstruation, constipation, bloating, diarrhea (due to infection or food intolerance), etc. As the food passes through the alimentary canal it is being broken into small molecules that can be absorbed. Sometime during the digestion of certain types of food (such as salad, beans, cabbage, cauliflower, etc) gas is produced. This gas may stay collected in one part of the intastine causing distension of the intestinal muscles which causes the pain.
Given the data that you described, it is likely that you experience that pain due to air collection in the intastines. You may consider avoiding the food that causes bloating. You may also consider avoiding carbonated drinks to avoid formation of air collection in the intestines. Do your best to avoid constipation.
Please keep in mind that I provide medical information only. I am not able to diagnose medical conditions online. Please contact your doctor for further advice and information about diagnosis and treatment options.