Hi thanks for asking g question. You have only watery diarrhea with pain.no other symptoms are present. Possibilities of here bacterial enterocolitis is present.it might be because of eating unhygienic food. Try course of antibiotic like that containing oflixacillin and ornidazole. Do your proctoscopy examination also for seeing whether fissure are present or not. Get your stool examined for any parasite. Continue with filtered or boiled water drinking along with fruit juice. Maintain good nutritional diet. If still no benefit then we will do USG abdomen like investigation as further work up. I hope I have solve your query