What should I do if I feel pain in my lower abdomen, stinging and gases after taking Macromax?

Good morning, I was prescribed the antibiotic Macromax 500mg. Yesterday I took 2 tablets and I had terrible diarrhea, even worse than on the 1st day of using the drug. I took 2 tablets of laremide at the beginning, one more for the evening. Helped with diarrhea. Today I took the last dose of Macromax at noon, I did not get diarrhea, but I feel pain in the lower abdomen, stinging and I have gas. What to do? Please advise