Surprisingly it can help settle an upset stomach. Some people take lemon water and it works by breaking down food and helping with stomach acids. Lemon has been used in the treatment of Norovirus, not only does it ease pain and nausea but it can be used as a disinfectant. It should be sipped gently so as not to cause further upset but used in the right quantity it can resolve stomach pain.
There are many other home remedies that can be used to settle the stomach such as apple cider vinegar, ginger, peppermint or even burnt toast. Some of these remedies might seem unlikely, especially the acidic type but they are known to work because they create a balance of the stomach acids.