It's a 49-year-old man with pain in his left lower abdomen. What's going on?

Left lower abdominal pain, accompanied by constipation, may be intestinal obstruction, suffering from diarrhea may be colitis, intestinal polyps, can not rule out the possibility of intestinal cancer. Left lower abdominal pain, accompanied by hematuria, may also be related to ureteral stones. Accompanied by abnormal urination and sexual dysfunction, may also be prostatitis.