Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Only morning diarrhea and upset stomach indicate that his problem is related to colon and rectum. The digestion is not proper or there is an element of proctocolitis that does not allow the stool to form well. Another reason can be intolerance to certain foods and beverages that can be known by keen observations and stopping and starting the foods by permutations and combinations to get the causative agents and stop them altogether. Get the stool tested for 3 consecutive days and if there is any evidence of an infection you can consult his doctor to get an appropriate dosage of an antibiotic, probiotic, and so on. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. T Chandrakant