Hi. Thanks for your history. Noted the history of stomach upset since past Saturday, same symptoms happened 2 weeks ago, and threw both the times, on Levothyroxin for hypothyroidism, started taking Nexium again which increased your problems and some friend suggested about low calcium. Your friend may not be a Doctor a the symptoms of low calcium is different. This may be related to the intestinal infection as you have recurrent symptoms and hence I would advise you the following: Get the stool and blood tested particularly for thyroid functions and to see for any chance of infection. If present you need to be started on an antibiotic and Metronidazole as well as probiotics and symptomatic treatment. If no infection is present then it may be possibly be due to intolerance or so or irritable sort of bowel, particularly so if all the investigations remains normal. Then get treated accordingly.