My 22 Year Old Son Has "like Clockwork" Diarrhea And

My 22 year old son has "like clockwork" diarrhea and vomiting that occurs at 6:15 am. He has stomach cramps, cannot eat until later in the day around 3:00-4:00. Has sweaty hands and feet but his feet are freezing. Doesn't have a fever. This has occurred 4x last week..in a row. And 3 days this week...every other day. He also has a rash. The rash has been present for some time. He saw Urgent Care who treated him for a bacterial/viral infection(?) and gave him a script for nasea. What should we be concerned about. He lives in Los Angeles.