Suggest Treatment For Painful Bowel Movement With Blood

Hi. So I recently came back from a trip to Japan. My bowel movements for two days after the trip were normal, however, after the second day, in the middle of the night, I had terrible diarrhea. I spent much of the night awake dealing with it, but come day time I had rid my body of all waste but I still had this pain in my stomach like I had to go. My mom got me anti diarrheal pills and I took 3 in one day. This didn t really do much because I was in too much pain to eat so I didn t produce any more waste. After sitting on the toilet, i felt constipated but only liquid would come out. It felt like something was blocking my anus from expelling waste. As I pushed, I tried to feel if there was any blockage, and instead of fecal matter, I felt a bulbous, thin sac of skin that blew up in my anus every time I strained. I was afraid that it was hemorrhoids so I attempted to stay away from trying to poop for a day. The pain was still there but I tried to ignore it because I knew nothing would come out. It is about 4 days later and I have since passed some bowel movements, yet nothing close to the ideal. It is still extremely painful to go and I continue to feel that no matter how much I push, some bit still will not expel. I would take a laxative but I am afraid that there is a problem with the muscles in my anus that won t allow them to stretch, and if I take a laxative I will have an even more painful urge to go but no place for it to escape. What should I do?