Gastrointestinal Side Effects: What They Are, Why They Happen, and How to Handle Them

When you take a new medicine, your body doesn’t always react the way you hope. One of the most common problems? gastrointestinal side effects, unpleasant reactions in the digestive tract caused by medications. Also known as stomach upset, these side effects include nausea, vomiting, diarrhea, bloating, and loss of appetite—and they’re more normal than you think. A lot of drugs, especially antibiotics, antidepressants, and blood pressure meds, irritate the gut lining or throw off your natural gut bacteria. You’re not imagining it. Your stomach is reacting.

Take sertraline, a common SSRI antidepressant. Up to 30% of people on sertraline get nausea or diarrhea, especially in the first few weeks. It’s not a sign the drug isn’t working—it’s just your body adjusting. The same goes for azilsartan medoxomil, a blood pressure medication. While it’s great for your heart, some people report mild stomach discomfort. Even lamivudine-zidovudine, an HIV combo drug, brings up digestive issues in many users. These aren’t rare accidents. They’re predictable, documented, and manageable.

What you need to know is this: not all stomach trouble means you should stop your medicine. Sometimes, taking the pill with food, switching the time of day, or adding a probiotic helps a lot. Other times, your doctor might lower the dose or swap in a different drug. The key is recognizing the pattern. If nausea hits every time you take your pill, or if diarrhea lasts more than a few days, that’s your body’s signal to talk to your provider. Ignoring it won’t make it go away—it might make it worse.

And it’s not just about pills. Even herbal supplements, like those in Renalka, a herbal blend for kidney support, can cause digestive upset if they’re not right for your system. The same goes for pain relievers, antifungals, and cholesterol meds. Your gut is sensitive. It’s not weak—it’s just doing its job.

Below, you’ll find real guides from people who’ve been there. They’ve dealt with sertraline nausea, figured out how to handle diarrhea from HIV meds, and learned when to push through and when to ask for help. No fluff. No guesswork. Just straight advice on what works, what doesn’t, and how to get back to feeling like yourself.