Flagyl and Upset Stomach: What Users Say

• Nel...
• Taken for less than 1 month
• October 18, 2020

For Bacterial Infection "I have been ill since the start of June this year. Finally received a diagnosis of BV last Thursday. Very concerned about taking this antibiotic after reading about so many bad experiences. Well, I am happy to report that after taking 4 tablets to date, the only side effects I have experienced are a bit of dizziness after taking the tablet and slight stomach cramps, which resolve after about an hour. Hope this feedback offers some reassurance to someone. Oops, almost forgot - I actually feel that I'm starting to get my life back - feel so much better."

• Net...
• Taken for less than 1 month
• November 17, 2019

For Bacterial Infection "Nah-ah. Never again. Worst medication I have ever taken. On my second day of taking this tablet, I was feeling nauseous. My appetite was bad, and my stomach felt sick. Headaches, fatigue, easily irritated. I dreaded taking it when the time came. It made me absolutely miserable. My resting heart rate went up to 105 bpm. Even raising my voice ever so slightly made my heart pound harder. It was very stressful. Steer clear. I felt stupid taking this medicine for side effects that were much worse than the reason I needed them for."

• non...
• August 27, 2016

For Diverticulitis "This drug caused uncontrollable diarrhea and stomach upset, and I had to stop taking it after just 2 days. This was given for mild diverticulitis, and I got better with a liquid diet for several days, then low-fiber soft food, and then graduated to regular foods. I had another bout of diverticulitis 4 months later and just did the diet - didn't go to doctors or use antibiotics. For my mild cases, this is the way to go. This drug caused more harm than good."

• Sna...
• October 2, 2018

For Bacterial Infection "I went into the hospital on Saturday with extreme stomach pain and constipation. CT scan and blood work showed colitis with a bacterial infection. Prescribed 500 mg Flagyl 3x a day and 500 mg Cipro 2x a day. I've taken Cipro before but had never heard of Flagyl. I made the mistake of reading reviews and became panicked. But most people don't leave reviews when things are good. I'm on day 3, but things are okay. I have to take it with milk. Keeps the nausea and metallic taste to a minimum. I have mild stomach upset (but nothing compared to before) and a headache. It's not pleasant, but I'm almost halfway through. My suggestion is to eat and drink different things. I also found spacing out the Flagyl and Cipro helped with nausea as well. The medicine seems to be working. And the side effects have been bearable so far. Take each review with a grain of salt and remember-every body is different and will respond to things differently."

• lov...
• Taken for less than 1 month
• June 22, 2020

For Bacterial Infection "I have SIBO, and my doctor prescribed Flagyl 250 mg 3 times/day for 14 days and Rifaximin 3 times/day for 14 days to treat SIBO (small intestinal bacterial overgrowth). Overall, my experience with Flagyl was unpleasant. I experienced moderate side effects that made me feel worse, so I stopped after 4 days and kept on the Rifaximin with no problems. On Flagyl, I experienced fatigue. When I tried to work out to boost energy, I felt horrendous: nauseous with flu-like symptoms. I experienced loss of appetite for normal healthy foods and found that I was binging on unhealthy foods. A slight metallic taste in my mouth, and a moderate feeling of upset stomach that came and went. Also, moderate bloating. If I had been extremely sick and Flagyl made me feel better, I may have kept on it, but for someone with mild SIBO, this drug wasn't worth it. If you're only mildly ill, I'd suggest finding an alternative medicine, if possible."

• Sea...
• Taken for less than 1 month
• March 26, 2015

For Diverticulitis "First off, don't forget that a lot of people are probably doing excellent with little to no problems with this antibiotic. Sort of like you never really hear from happy customers, usually the unsatisfied ones. Also, that everyone's body reacts differently. ...that being said, Holy Cow, the nausea! Ugh... Stomach cramps and pretty much constant nausea all day today (day 2). Eventually, had to leave work early. Pepto did not help. Going to try taking Nauzene with me to work tomorrow, see if it helps. (OTC nausea medication - a lifesaver in the past) Taking it with Cipro. Been on this combo before for my diverticulitis without so many stomach problems. Still a better option than the huge waves of pain from a flare-up."

• Anonymous
• Taken for less than 1 month
• October 30, 2012

For Bacterial Infection "My doctor gave me this because I had bacterial vaginosis. Not even 12 hours into my first dose, I got the metallic taste in my mouth, then severe stomach cramps and nausea. I'm on day 5 and have had bouts of nausea throughout the course of my medication. My appetite has gone way, way down, and I'm so tired! I literally will sleep 12 hours and then get up for 2, then go back to bed for another 4! Having trouble staying awake at work, but it is doing its job!"

• Eva...
• July 28, 2009

For Bacterial Infection "I had a vaginal infection and was prescribed Flagyl to cure it. I hated the immediate awful taste in my mouth, and it dissolved immediately upon hitting my tongue. I only experienced the awful taste and some slight stomach upset as side effects. The infection began to clear up after 3 days of a 7-day prescription. I recommend it, and drink something fruity with it. Also, DO NOT DRINK ALCOHOL AT ALL while on this medication OR FOR 3 DAYS AFTER YOU STOP TAKING IT. You WILL have severe vomiting, heaving, and dizziness."

• UN...
• Taken for less than 1 month
• November 9, 2019

For Bacterial Infection "Prescribed this medicine for an infection I got after getting an IUD inserted. 500 mg metronidazole twice a day. Took them at 8 am day one. No issues day two. Up at 4 am, had symptoms of bloating, stomach gurgling, cramps, explosive diarrhea, extremely liquid stool, pain. All subsided by 11 am next day. Day three. Up at 1 am. Bloating, stomach gurgling, doubled from the night before. I had cramps, diarrhea, but not as bad as the night before, and I swore that I was done with this medicine. Drank a probiotic yogurt, and it’s been a while, 20 minutes with no gurgling... nope, I was wrong. Here we go again..."

• Wor...
• Taken for less than 1 month
• November 9, 2015

For Bacterial Infection "Everyone's body will react differently to meds, genetics. Just because I had a bad experience doesn't mean you will. Took with a full stomach of bland food, 16 oz water, and took a daily probiotic. My experience with this medication was horrible. I was unbearably anxious, had a rapid heartbeat, intense pelvic pressure, bad stomach cramping, nonstop nausea, vomiting, and explosive diarrhea. This was my second time with this medication, with the same bad reaction. I had to discontinue both times. It took 3 days to start feeling better, 5 to 7 until normal. I'll never take this medication again. I'm sure it's good for others, but not me. I had cancer, so I've taken a lot of medications. Never had to stop another medication from side effects before, but I was scared to the point of going to the ER. Never again."

• Naa...
• Taken for less than 1 month
• March 12, 2019

For Bacterial Infection "I have taken Flagyl multiple times for BV. I hate it each time. I tried clindamycin, but it wasn’t as effective. I took the pills with chocolate milk for the first few days, then orange juice. Then I finally saw where to wrap a fruit roll-up around the pill. I wish I would’ve known about that a long time ago. It helped a lot. My side effects were: dizzy, drowsy, stomach ache, heartburn, kind of blurry vision, headaches, back pain, frequent urination, dark urine, not much diarrhea, nausea. Finally, I didn’t have a metallic taste, but the aftertaste was awful. After taking the medication, it did give me a yeast infection, which was expected. Really, please try the fruit roll-up method, it helped a lot even with my last tablet."

• adi...
• December 29, 2011

For Bacterial Infection "I just finished a 10-day treatment of 500 mg every 12 hours. I am so glad it is over. I experienced stomach aches, a metallic taste in my mouth, which I am still experiencing, as well as tingling/numbness in my tongue. I am also experiencing itchy and a burning sensation in the vaginal area, it is uncomfortable. I hope it goes away soon. The only good thing about all this is that I don't have that fishy smell anymore."

• Anonymous
• December 11, 2008

For Bacterial Infection "I took this in February of 2008, and in December 2008, I was diagnosed with the same bacterial infection again. The doctor said this is the best medicine available to kill the bacteria. The pills are horrible to take since they are not coated. I've experienced the metallic taste and stomach upset feelings. However, if they work, I am willing to withstand this temporary inconvenience."

• AT...
• Taken for less than 1 month
• April 10, 2019

For Diverticulitis "This is the 4th time I have had diverticulitis, and one of the things I dread is having to take 500 mg of Cipro (2x a day) and 500 mg of Flagyl (3x a day) for 10 days. The nausea and stomach ache are horrible. I am now on the 7th day, and this morning I began thinking about why the problems remain so many hours after I take the drugs. I thought perhaps the drugs were not dissolving properly, so I cut the pills in half and took them in 2 pieces. I have not had nausea or stomach pain today. It did not help the fatigue and weakness, however."

• Ser...
• Taken for less than 1 month
• October 24, 2019

For Bacterial Infection "I took Flagyl x 2 for 5 days for BV last month, having suffered bacterial vaginitis for over a year. I had tried natural remedies that just did not work, so as a last resort in utter frustration, I turned to Flagyl despite having read such awful reviews about it. I experienced no side effects at all from it until the very last day when I suffered a mild upset stomach. All signs of the BV were completely gone by the end of the week following when I completed the course of antibiotics, which was fantastic, however, since then I have reasonably frequent stomach upsets after eating. I'd rather have that rather than have BV, so a small price to pay. As antibiotics kill off all bacteria, both good and bad, I have now been loading up on probiotics in an attempt to put good bacteria back into my body. This medication did work for me for BV, and I'm so thankful that it's gone at last."

• Alb...
• December 11, 2017

For Bacterial Infection "This drug almost killed me. I took 400 mg twice a day for 5 days. The first day was okay. The second day, I experienced stomachache, agitation, insomnia, nausea, hallucination, and nightmares. The third day, I rushed to the hospital with blurred vision, which lasted for over 11 hours. Never again."

• med...
• Taken for less than 1 month
• July 27, 2015

For Bacterial Infection "I went on a holiday to Thailand and developed a bloated stomach with wind and later diarrhea. The doctor prescribed Flagyl to kill any bugs in the intestine. We know that in these countries it is rather easy to get a bug from foods. After many trips, I finally got a Bangkok belly. After taking 400 mg three times a day, I felt some relief the next day. Felt good. Then the next day, I woke up feeling terrible. I had sneezing, a runny nose, a feeling of tightness in the nose (harder to breathe), asthma, dry lips, rashes on the hands, body aches, lack of appetite, feeling lethargic and tired, along with wind in the stomach and slight nausea. Diarrhea was almost gone. Most side effects were happening to me on the fourth day."

• mis...
• July 6, 2012

For Bacterial Infection "I've been taking this medication for 5 days now. I'm on it for 10 days, 3 times a day, and I'm being treated for C. diff. Before I started this medication, I was in severe pain, diarrhea, weight loss, constantly urinating. Now my abdominal pain is minimal, I'm holding weight. Gained a few pounds. Still having constant urination, not quite as much, and still having an upset stomach, diarrhea. Now going back to the Dr. to see if I still have C. diff."

• Fru...
• November 5, 2019

For Bacterial Infection "I was prescribed Flagyl for bacterial vaginitis (BV). I knew within two days that it wasn’t working, but proceeded to take the medicine. On day six, I returned to the doctor and was again tested, and as I suspected, still had BV. The medication caused an upset stomach and obviously didn’t treat the infection. I had to fight with the doctor to be prescribed clindamycin. I’m starting clindamycin today with the hopes that it will have a better impact on the BV."

• Not...
• Taken for less than 1 month
• February 9, 2025

For Bacterial Infection "So I have panic disorder and anxiety like many other people here. I delayed taking it because of side effects, like many people here. However, my approach was to take one pill on the first day to see how I responded, then two on the second. I am NOT a doctor, so don’t do this if you don’t want to. But for me, it helped the anxiety and also helped to discover how I would tolerate it. I take it as prescribed now and have had mild stomach upset, but nothing serious or debilitating. I notice dizziness occasionally, but that’s likely because you have to drink quite a bit of water with Flagyl, and I am not great at drinking water. I drink coffee and have no issues with anxiety or increased heart rate. I went for a 6-mile walk, no issues at all. I’ve also not had any headaches associated with it either. So, for those who are afraid to take it, take it as prescribed and trust that your doctor prescribed it because the benefits outweigh the costs."

• Bes...
• December 7, 2009

For Bacterial Infection "I have used this medication several times for bacterial infections. And they do a great job, but this time I am having a headache every day I've been using it and an upset stomach, but I guess it's worth it to get rid of the infection."

• Lri...
• June 22, 2016

For Bacterial Infection "Working antibiotic, definitely strong on the side effects, feels like I have to urinate as if I was pregnant, insomnia for sure. Thank God I only need to take this pill for a little time. Stomach upset all the time, not when eating but early in the morning, feels the need to vomit."

• Han...
• August 7, 2017

For Bacterial Infection "Literally, I feel like this is the worst medication I've ever been on. The surgeon put me on this for an oral abscess... been dying for like 5 days and two more to go. Can't sleep, but I'm so tired. Eat, look at light, worst headache ever. Stomach hurts, but this headache makes me forget about that. All in all, I feel horrible."

• ang...
• January 22, 2021

For Bacterial Infection "If you are a coffee drinker or smoker (weed), definitely try consuming less of both products during the course of Flagyl. It’s now my second time taking it, and it’s very effective for my BV. But the side effects are a downside. Eating BRAT foods (will help the diarrhea or upset stomach) and drinking lots, LOTS, of water is necessary. Also, getting lots of probiotics and electrolytes have helped me feel better. I’ve noticed that it makes the effect of caffeine and weed almost ten times stronger, and not in a good way. So be careful and watch your heartbeat/blood pressure. This worked way better for me than clindamycin. I think you do feel off, and it’s noticeable, but it’s better than the symptomatic BV I’ve been having."

• gar...
• Taken for less than 1 month
• August 1, 2021

For Bacterial Infection "This happened twice with two different OB/GYN doctors. I went in for my regular Pap smears and walked out of the office with prescriptions for Flagyl. Mind you, in both cases, I had no symptoms of a vaginal bacterial infection. The first time I took the medication, I had horrible side effects: upset stomach, feeling of illness, fatigue, metallic taste in my mouth. After finishing the meds, I ended up with a yeast infection because the meds got rid of all the good vaginal bacteria. I was recently prescribed another round of Flagyl after a routine Pap smear three years later with a different doctor, and again I've had no symptoms of a vaginal infection. I refuse to take the meds. I'm wondering if OB/GYNs are getting kickbacks for writing this prescription. 0 stars!!!!"