Key takeaways
Lactulose (Constulose) and docusate/senna (Senna-S) are both used to treat constipation, but they work differently and have distinct characteristics. Lactulose is an osmotic laxative that draws fluid into the gut to soften stool, and it typically takes 1 to 2 days to work. It is available only by prescription and can be used in people with kidney or liver problems. Common side effects include stomach pain and gas. On the other hand, docusate/senna is a combination of a stool softener and a stimulant laxative, which works by both softening the stool and stimulating the intestines to push it out. It usually works within 6 to 12 hours and is available over-the-counter. Docusate/senna is recommended for short-term use and can cause stomach cramps and loose stools. While lactulose is not a first-choice laxative due to its side effects and slower action, docusate/senna is favored for its quicker relief but should not be used for more than a week without consulting a healthcare professional.
