The large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. Water is absorbed here and the remaining waste material is stored in the rectum as feces before being removed by defecation. The colon is the longest portion of the large intestine, and the terms are often used interchangeably but most sources define the large intestine as the combination of the cecum, colon, rectum, and anal canal. Some other sources exclude the anal canal.
Ulcerative colitis (UC) is a long-term condition that results in inflammation and ulcers of the colon and rectum. The primary symptoms of active disease are abdominal pain and diarrhea mixed with blood (hematochezia). Weight loss, fever, and anemia may also occur. Often, symptoms come on slowly and can range from mild to severe. Symptoms typically occur intermittently with periods of no symptoms between flares. Complications may include abnormal dilation of the colon (megacolon), inflammation of the eye, joints, or liver, and colon cancer.
Colorectal cancer (CRC), also known as bowel cancer, colon cancer, or rectal cancer, is the development of cancer from the colon or rectum. Signs and symptoms may include blood in the stool, a change in bowel movements, weight loss, and fatigue. Most colorectal cancers are due to old age and lifestyle factors, with only a small number of cases due to underlying genetic disorders. Risk factors include diet, obesity, smoking, and lack of physical activity. Dietary factors that increase the risk include red meat, processed meat, and alcohol. Another risk factor is inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis. Some of the inherited genetic disorders that can cause colorectal cancer include familial adenomatous polyposis and hereditary non-polyposis colon cancer; however, these represent less than 5% of cases. It typically starts as a benign tumor, often in the form of a polyp, which over time becomes cancerous.
A fistula in anatomy is an abnormal connection between two hollow spaces, such as blood vessels, intestines, or other hollow organs. Types of fistula can be described by their location. Anal fistulas connect between the anal canal and the perianal skin. Anovaginal or rectovaginal fistulas occur when a hole develops between the anus or rectum and the vagina. Colovaginal fistulas occur between the colon and the vagina. Urinary tract fistulas are abnormal openings within the urinary tract or an abnormal connection between the urinary tract and another organ such as between the bladder and the uterus in a vesicouterine fistula, between the bladder and the vagina in a vesicovaginal fistula, and between the urethra and the vagina in urethrovaginal fistula. When occurring between two parts of the intestine, it is known as an enteroenteral fistula, between the small intestine and the skin as an enterocutaneous fistula, and between the colon and the skin as a colocutaneous fistula.
Diverticulosis is the condition of having multiple pouches (diverticula) in the colon that are not inflamed. These are outpockets of the colonic mucosa and submucosa through weaknesses of muscle layers in the colon wall. Diverticula do not cause symptoms in most people. Diverticular disease occurs when diverticula become clinically inflamed, a condition known as diverticulitis.
Rectal foreign bodies are large foreign items found in the rectum that can be assumed to have been inserted through the anus, rather than reaching the rectum via the mouth and gastrointestinal tract. It can be of clinical relevance if the patient cannot remove it the way they intended. Smaller, ingested foreign bodies, such as bones eaten with food, can sometimes be found stuck in the rectum upon x-ray and are rarely of clinical relevance.
Colorectal surgery is a field in medicine dealing with disorders of the rectum, anus, and colon. The field is also known as proctology, but this term is now used infrequently within medicine and is most often employed to identify practices relating to the anus and rectum in particular. The word proctology is derived from the Greek words πρωκτός proktos, meaning "anus" or "hindparts", and -λογία -logia, meaning "science" or "study".
Ileostomy is a stoma constructed by bringing the end or loop of small intestine out onto the surface of the skin, or the surgical procedure which creates this opening. Intestinal waste passes out of the ileostomy and is collected in an external ostomy system which is placed next to the opening. Ileostomies are usually sited above the groin on the right hand side of the abdomen.
A fecal impaction or an impacted bowel is a solid, immobile bulk of feces that can develop in the rectum as a result of chronic constipation. Fecal impaction is a common result of neurogenic bowel dysfunction and causes immense discomfort and pain. It treatment includes laxatives, enemas, and pulsed irrigation evacuation (PIE) as well as digital removal. It is not a condition that resolves without direct treatment.
Colectomy is bowel resection of the large bowel (colon). It consists of the surgical removal of any extent of the colon, usually segmental resection. In extreme cases where the entire large intestine is removed, it is called total colectomy, and proctocolectomy denotes that the rectum is included.
Megacolon is an abnormal dilation of the colon. This leads to hypertrophy of the colon. The dilation is often accompanied by a paralysis of the peristaltic movements of the bowel. In more extreme cases, the feces consolidate into hard masses inside the colon, called fecalomas, which can require surgery to be removed.
A lower anterior resection, formally known as anterior resection of the rectum and colon and anterior excision of the rectum or simply anterior resection, is a common surgery for rectal cancer and occasionally is performed to remove a diseased or ruptured portion of the intestine in cases of diverticulitis. It is commonly abbreviated as LAR.
The rectum is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. The adult human rectum is about 12 centimetres (4.7 in) long, and begins at the rectosigmoid junction at the level of the third sacral vertebra or the sacral promontory depending upon what definition is used. Its diameter is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. It terminates at the level of the anorectal ring or the dentate line, again depending upon which definition is used. In humans, the rectum is followed by the anal canal which is about 4 centimetres (1.6 in) long, before the gastrointestinal tract terminates at the anal verge. The word rectum comes from the Latin rectumintestinum, meaning straight intestine.
Rectal discharge is intermittent or continuous expression of liquid from the anus. Normal rectal mucus is needed for proper excretion of waste. Otherwise, this is closely related to types of fecal incontinence but the term rectal discharge does not necessarily imply degrees of incontinence. Types of fecal incontinence that produce a liquid leakage could be thought of as a type of rectal discharge.
Anismus or dyssynergic defecation is the failure of normal relaxation of pelvic floor muscles during attempted defecation. It can occur in both children and adults, and in both men and women. It can be caused by physical defects or it can occur for other reasons or unknown reasons. Anismus that has a behavioral cause could be viewed as having similarities with parcopresis, or psychogenic fecal retention.
The colorectal adenoma is a benign glandular tumor of the colon and the rectum. It is a precursor lesion of the colorectal adenocarcinoma. They often manifest as colorectal polyps.
John Cedric Goligher (1912–1998) was a British surgeon who specialised in diseases of the rectum and colon and in coloproctology. He was "renowned worldwide" and had "a national and international reputation" He is considered to have been "one of the preeminent clinical investigative surgeons" of his time.
Steven D. Wexner is an American surgeon and physician. He is Director of the Ellen Leifer Shulman and Steven Shulman Digestive Disease Center at Cleveland Clinic Florida. Wexner has received numerous regional, national, and international research awards. Through his multiple academic appointments, Wexner personally trains 15-20 surgeons each year, and he educates thousands more around the world through conferences and lectures. He is a resource for his colleagues from around the world for referral of patients with challenging or complex problems. In 2020, he was elected Vice-Chair of the Board of Regents of the American College of Surgeons for a one year term. Since 1990. he has served as Symposium Director of the Cleveland Clinic Annual International Colorectal Disease Symposium. The Symposium was held in Fort Lauderdale or Boca Raton every year from 1990 to 2019. Since 2020, the Symposium has expanded to include host locations outside of the USA with interruptions during the pandemic years of 2021-2022.
Segmental colitis associated with diverticulosis (SCAD) is a condition characterized by localized inflammation in the colon, which spares the rectum and is associated with multiple sac-like protrusions or pouches in the wall of the colon (diverticulosis). Unlike diverticulitis, SCAD involves inflammation of the colon between diverticula, while sparing the diverticular orifices. SCAD may lead to abdominal pain, especially in the left lower quadrant, intermittent rectal bleeding and chronic diarrhea.
John Percy Lockhart-Mummery FRCS, was a British surgeon at St Mark's Hospital, London, who devised a classification of rectal cancer and described familial polyposis which led to the formation of the polyposis registry. He was the author of several books, including Diseases of the Rectum and Colon and their Surgical Treatment (1923) and The Origin of Cancer (1934). His work on colorectal surgery earned him the nickname "King Rectum".
