Hi thanks for asking question. Noted you are diagnosed parasite infection. For that you are receiving metronidazole containing drug which useful in chronic amebiasis as well as anaerobic bacterial infection. Diarrhea could be as side effect of drug. Meanwhile folllow below o instructions.... -green leafy veg more. -more water -small meal taken at frequent interval -semisolid diet good for few days -avoid excess smoking and alcohol -avoid excess spicy food If still your symptoms increasing then USG done.and still if needed colonoscopy done and biopsy taken send for his to pathological examination.It might reveal microscopic colitis or inflammatory bowel disease like condition. Wish you good health. Take care