- Sudden, severe ulcerative colitis This is the main reason for emergency surgery for ulcerative colitis. About 15 percent of people with ulcerative colitis have an attack of the disease so severe that medications, even intravenous steroids, cannot control the symptoms. Surgery may be necessary if medications are unable to bring the attack under control. Sudden, severe ulcerative colitis also includes uncontrolled bleeding in the colon (which is quite rare) and toxic megacolon. Toxic megacolon is caused by severe inflammation that leads to rapid enlargement of the colon. This potentially life-threatening complication requires immediate treatment and surgery
- Perforation of the colon Chronic inflammation of the colon may weaken the wall to such an extent that a hole occurs. This is potentially life threatening because the contents of the intestine can spill into the abdomen and cause a serious infection called peritonitis.
- Intestinal obstruction or blockage Chronic inflammation in the intestines can cause the walls of digestive organs to thicken or form scar tissue. This can narrow a section of intestine (called a stricture), which may lead to an intestinal blockage. Nausea and vomiting or constipation may be signs of a stricture.
- Excessive bleeding in the intestine This is a rare complication of Crohn’s disease. Surgery is performed only if bleeding cannot be controlled by other means.
- Perforation of the bowel As with ulcerative colitis, chronic inflammation may weaken the wall of the intestine to such an extent that a hole occurs. Occasionally, a portion of the bowel near a stricture can also expand, causing the wall to weaken and a hole to occur.
- Fistula Inflammation can cause ulcers (sores) to form in the inside wall of the intestines or other organs. These ulcers can extend through the entire thickness of the bowel wall and form a tunnel to another part of the intestine, between the intestine and another organ such as the bladder or vagina, or to the skin surface. These are called fistulas. Fistulas can also form around the anal area, and may cause drainage of mucus or stool from an area adjacent to the anus. Repair of this connection requires surgery.
- Abscess An abscess is a collection of pus, which can develop in the abdomen, pelvis, or around the anal area. It can lead to symptoms of severe pain in the abdomen, painful bowel movements, discharge of pus from the anus, fever, or a lump at the edge of the anus that is swollen, red, and tender. An abscess requires not only antibiotics, but also surgical drainage of the pus cavity to allow for healing
- Toxic megacolon As with ulcerative colitis, severe inflammation can lead to toxic megacolon and require immediate treatment and surgery."