Stomach Cramps. On Anti Amoebic Tablets. Why Hunger And Weakness?

Hi, My mother is 60yrs of age and she is in good health but past 15days she is suffering stomach cramps so, our family doctor gave her anti amoebic tablet 2tablets at a time ,sorry don t remember the name she felt better after taking the medicine but at the same time she had cold so she is been taking medicines for cold ,but past some days even after taking vitamin tablets and having her food she feels hungry and weakness .Please can you tell me the reason? Is it due to acidity?