Hi. Thanks for asking in Healthcare Magic. Probably you are having gastritis. Since you have not mentioned the names of the pills, it is difficult to give you a specific answer. Most of the pills are meant to be taken after food and not on empty stomach unless specified or unless they are enteric coated. Although you have mentioned that you take them in the afternoon, you have not indicated if you are taking them after food. When taken on empty stomach, muscle relaxants can cause gastritis. Also the problem may be aggravated because you are skipping your dinner. Drugs like Rabeprazole are given to treat gastritis but check with your physician before you take any medication as the diagnosis of gastritis needs to be confirmed. I hope this is useful to you.