Not all antibiotics have gastrointestinal side effects, but some antibiotics are damaging to the stomach. 1. Antibiotics have antibacterial and bactericidal effects, it can resist the attack of pathogens in the human body, it will also cause some damage to the human body when it kills pathogenic bacteria. Part of the antibiotic through the oral cavity into the stomach, through the gastrointestinal tract absorption to reach the various tissues of the body, in this process antibiotics may stimulate the gastric mucosa. 2. The human body in taking antibiotics try to take after meals, or with some of the drugs to protect the gastric mucosa, as far as possible to reduce its stimulation of the stomach. People with bad stomachs are advised to take antibiotics such as amoxicillin and clarithromycin under the guidance of a doctor. The stomach belongs to the digestive organs, in daily life, pay attention not to stimulate the stomach, eat more light food, eat less or do not eat spicy stimulating products, such as chili peppers, garlic, strong wine. If there is stomach discomfort, it is recommended to timely hospital treatment.