The pain of gas against the anus is considered to be caused by abnormal anal excretion or stopping of excretion, which leads to a large amount of gas collecting in the intestines causing abdominal distension, and the spasm and contraction of intestinal tubes causing abdominal pain, which is considered to be intestinal obstruction. Intestinal obstruction is divided into incomplete intestinal obstruction and complete intestinal obstruction, causing intestinal obstruction due to many reasons, intestinal obstruction according to different etiologies, divided into mechanical intestinal obstruction, dynamic intestinal obstruction, blood transport intestinal obstruction, common dry knot stool, intestinal tumors, intestinal foreign body, etc., leading to intestinal lumen obstruction caused by mechanical intestinal obstruction. Hemorrhoids, if more serious leading to prolapse of hemorrhoids, can also lead to intestinal lumen blockage and cause pain, bloating, etc. Pelvic tumors pressing on the rectum can also lead to pain at the anus and discomfort of flatulence. Anal pain, flatulence, it is recommended to go to the hospital gastrointestinal surgery or anorectal surgery outpatient clinic for anal fingerprinting and anoscopy, and then enteroscopy.