Hi, Thanks for posting your query. With the available described details, there appears to high possibility of Acute gastroenteritis. Although Amoxycillin may cause antibiotic associated diarrhea but it is not associated with spasmodic abdominal pain; so there is high possibility of intestinal infection. You should consult with internal medicine specialist/ gastroenterologist and should go for thorough check up. You should go for complete blood count, erythrocyte sedimentation rate, ultrasound imaging, and serum electrolytes, renal function test. You should take complete antibiotic therapy, antispasmodics, probiotics, antipyretics, if needed. Frequent watery diarrhea and vomiting may cause weakness due to loss potassium. You should maintain your hydration status by taking potassium rich liquids. Take soft diet along with yogurt and banana. Avoid milk and all milk related products. Take care, Dr. Mayank Bhargava