Crohn's disease is a chronic inflammatory bowel disease characterized by recurrent episodes of intestinal inflammation, primarily manifesting as diarrhea and abdominal pain. Unlike ulcerative colitis, inflammation can occur anywhere in the gastrointestinal tract, though it most frequently affects the ileum and colon, involving all layers of the intestinal wall. Symptoms may be non-specific and progress gradually, often delaying diagnosis. About one-third of patients have colonic disease, another third have ileocolic disease, and the remaining third have isolated ileal disease. Systemic symptoms such as chronic fatigue, weight loss, and low-grade fevers are common. Organs such as the skin and joints can also be affected. Complications can include bowel obstructions, fistulas, nutrition problems, and an increased risk of intestinal cancers.
Ulcerative colitis (UC) is one of the two types of inflammatory bowel disease (IBD), with the other type being Crohn's disease. It 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.
Hematochezia is a form of blood in stool, in which fresh blood passes through the anus while defecating. It differs from melena, which commonly refers to blood in stool originating from upper gastrointestinal bleeding (UGIB). The term derives from Greek αἷμα ("blood") and χέζειν. Hematochezia is commonly associated with lower gastrointestinal bleeding, but may also occur from a brisk upper gastrointestinal bleed. The difference between hematochezia and rectorrhagia is that rectal bleeding is not associated with defecation; instead, it is associated with expulsion of fresh bright red blood without stools. The phrase bright red blood per rectum is associated with hematochezia and rectorrhagia.
Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine, with Crohn's disease and ulcerative colitis (UC) being the principal types. Crohn's disease affects the small intestine and large intestine, as well as the mouth, esophagus, stomach and the anus, whereas UC primarily affects the colon and the rectum.
Diverticulitis, also called colonic diverticulitis, is a gastrointestinal disease characterized by inflammation of abnormal pouches—diverticula—that can develop in the wall of the large intestine. Symptoms typically include lower abdominal pain of sudden onset, but the onset may also occur over a few days. There may also be nausea, diarrhea or constipation. Fever or blood in the stool suggests a complication. People may experience a single attack, repeated attacks, or ongoing "smouldering" diverticulitis.
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.
Gastrointestinal diseases refer to diseases involving the gastrointestinal tract, namely the esophagus, stomach, small intestine, large intestine and rectum; and the accessory organs of digestion, the liver, gallbladder, and pancreas.
Colitis is swelling or inflammation of the large intestine (colon). Colitis may be acute and self-limited or long-term. It broadly fits into the category of digestive diseases.
Toxic megacolon is an acute form of colonic distension. It is characterized by a very dilated colon (megacolon), accompanied by abdominal distension (bloating), and sometimes fever, abdominal pain, or shock.
In medicine, the ileal pouch–anal anastomosis (IPAA), also known as restorative proctocolectomy (RPC), ileal-anal reservoir (IAR), an ileo-anal pouch, ileal-anal pullthrough, or sometimes referred to as a J-pouch, S-pouch, W-pouch, or a pelvic pouch, is an anastomosis of a reservoir pouch made from ileum to the anus, bypassing the former site of the colon in cases where the colon and rectum have been removed. The pouch retains and restores functionality of the anus, with stools passed under voluntary control of the person, preventing fecal incontinence and serving as an alternative to a total proctocolectomy with ileostomy.
Diverticular disease is when problems occur due to diverticulosis, a benign condition defined by the formation of pouches (diverticula) from weak spots in the wall of the large intestine. This disease spectrum includes diverticulitis, symptomatic uncomplicated diverticular disease (SUDD), and segmental colitis associated with diverticulosis (SCAD). The most common symptoms across the disease spectrum are abdominal pain and bowel habit changes such as diarrhea or constipation. Otherwise, diverticulitis presents with systemic symptoms such as fever and elevated white blood cell count whereas SUDD and SCAD do not. Treatment ranges from conservative bowel rest to medications such as antibiotics, antispasmodics, acetaminophen, mesalamine, rifaximin, and corticosteroids depending on the specific conditions.
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.
Blood in stool looks different depending on how early it enters the digestive tract—and thus how much digestive action it has been exposed to—and how much there is. The term can refer either to melena, with a black appearance, typically originating from upper gastrointestinal bleeding; or to hematochezia, with a red color, typically originating from lower gastrointestinal bleeding. Evaluation of the blood found in stool depends on its characteristics, in terms of color, quantity and other features, which can point to its source, however, more serious conditions can present with a mixed picture, or with the form of bleeding that is found in another section of the tract. The term "blood in stool" is usually only used to describe visible blood, and not fecal occult blood, which is found only after physical examination and chemical laboratory testing.
Lower gastrointestinal bleeding (LGIB) is any form of gastrointestinal bleeding in the lower gastrointestinal tract. LGIB is a common reason for seeking medical attention at a hospital's emergency department. LGIB accounts for 30–40% of all gastrointestinal bleeding and is less common than upper gastrointestinal bleeding (UGIB). It is estimated that UGIB accounts for 100–200 per 100,000 cases versus 20–27 per 100,000 cases for LGIB. Approximately 85% of lower gastrointestinal bleeding involves the large intestine, 10% are from bleeds that are actually upper gastrointestinal bleeds, and 3–5% involve the small intestine.
Stercoral ulcer is an ulcer of the colon due to pressure and irritation resulting from severe, prolonged constipation due to a large bowel obstruction, damage to the autonomic nervous system, or stercoral colitis. It is most commonly located in the sigmoid colon and rectum. Prolonged constipation leads to production of fecaliths, leading to possible progression into a fecaloma. These hard lumps irritate the rectum and lead to the formation of these ulcers. It results in fresh bleeding per rectum. These ulcers may be seen on imaging, such as a CT scan but are more commonly identified using endoscopy, usually a colonoscopy. Treatment modalities can include both surgical and non-surgical techniques.
Faecal calprotectin is a biochemical measurement of the protein calprotectin in the stool. Elevated faecal calprotectin indicates the migration of neutrophils to the intestinal mucosa, which occurs during intestinal inflammation, including inflammation caused by inflammatory bowel disease. Under a specific clinical scenario, the test may eliminate the need for invasive colonoscopy or radio-labelled white cell scanning.
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.
Colonic ulcer can occur at any age, in children however they are rare. Most common symptoms are abdominal pain and hematochezia.
Checkpoint inhibitor induced colitis is an inflammatory condition affecting the colon (colitis), which is caused by cancer immunotherapy. Symptoms typically consist of diarrhea, abdominal pain and rectal bleeding. Less commonly, nausea and vomiting may occur, which may suggest the present of gastroenteritis. The severity of diarrhea and colitis are graded based on the frequency of bowel movements and symptoms of colitis, respectively.
A rectal stricture is a chronic and abnormal narrowing or constriction of the lumen of the rectum which presents a partial or complete obstruction to the movement of bowel contents. A rectal stricture is located deeper inside the body compared to an anal stricture. Sometimes other terms with wider meaning are used, such as anorectal stricture, colorectal stricture or rectosigmoid stricture.
