Whats causing left side stomach pain? More

[Stocksinc]

Please help. I’m on ranitidine 300 2x’s day. This has been months daily worse. Thought I had kidney stone. Ck’d no Stones. Pain under rib. Pain is from under left rib to kidney. I am gassed up, with loose stool. I have slimy discharge anally. I’m wondering if it’s the ranitidine causing. Urologist has no clue. Reg Dr wants me to have colonoscopy. What is is, what do I do. I might go to area Hosp. ER tomorrow. Tied of constant pain. Father had cancers. My PSA was high recently. Please help. Pray for me.