Donnatal is a prescription medication that contains a combination of four different drugs, including hyoscyamine, atropine, scopolamine, and phenobarbital. This medication is mainly used to treat various digestive disorders, such as irritable bowel syndrome and stomach ulcers. While there are no direct synonyms for Donnatal, several pharmaceutical companies manufacture similar medications that contain hyoscyamine, such as Levsin and Anaspaz. These drugs work in a similar way by relaxing the muscles in the digestive system and reducing spasms. It's important to note that all of these medications should only be taken under the guidance of a doctor as they can cause various side effects.