I started melatonin (10 mg) after a nurse friend told me how much it had helped her. I started taking it about a week after my bout of diverticulitis cleared up. I almost immediately developed diarrhea and loose stools along with serious cramping. I was also waking up with a headache every day. I thought I had not recovered from the diverticulitis, but am now wondering if it is the melatonin. I have severe cramping on the left side, but doesn't feel the same as before. Hoping it is gas. Have been off the melatonin for about 5 days. Diarrhea seems better, just cramping now. Does anyone have suggestions on how to get rid of the gas? At least I hope it's gas! Have tried Pepcid, but doesn't seem to help.