Hello. There could definitely be a link between ppi's (omeprazole, nexium.) and rosacea, because suppressing stomach acid will interfere with absorption, let undigested food reach the intestine, and let pathogens come into the gut. Can Omeprazole Cause Diarrhea In Dogs. What Causes Yellow Diarrhea in Dogs? - Dog's Upset StomachYellow diarrhea in dogs is something that may alarm dog owners considering that a normal dog’s poop color is considered to be brown. Omeprazole is in a class of drugs known as proton pump inhibitors that decrease stomach acid. Known as Prilosec in its over-the-counter form, omeprazole is prescribed for acid reflux disease, heartburn and stomach ulcers. Side Effects. Drug information provided by: IBM Micromedex. Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. Summary. Skin spots - red is found among people who take Omeprazole, especially for people who are female, 60+ old , have been taking the drug for 6 - 12 months, also take medication Furosemide, and have Pneumonia. Omeprazole is in a class of drugs known as proton pump inhibitors that decrease stomach acid. Known as Prilosec in its over-the-counter form, omeprazole is prescribed for acid reflux disease, heartburn and stomach ulcers. I was put on Omeprazole on a Friday and by Tuesday my whole torso had came out in a rash of small spots. I have been told to stop taking the tablet and told to use Antihistamines. Brief Answer: It might be due to omeprazole. Detailed Answer: Hello! I am glad that your symptoms are improving by taking Omeprazole. You don t disturb me at all.I am happy if I can help you ease your anxiety and make you feel better. Regarding these red spots on your chest ,it is possible that. Along with its needed effects, omeprazole/sodium bicarbonate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention. Although not all of these side effects may occur, if they do occur they may need medical attention. For the Consumer. Applies to omeprazole: oral capsule delayed release, oral packet, oral powder for suspension, oral tablet delayed release. Along with its needed effects, omeprazole may cause some unwanted effects.