196 articles
Polyposis syndrome
Polyposis syndrome: hereditary conditions with multiple gastrointestinal polyps and elevated cancer risk, including FAP (APC, dominant), MAP (MUTYH, recessive), hamartomatous syndromes (PJS, JPS, PTEN), and serrated polyposis, the most common type.
Polyps of small intestine
Polyps of small intestine (ICD-11 DA98) are benign tissue masses protruding into the small-bowel lumen: hamartomas, hyperplastic, inflammatory fibroid polyps, and lymphoid hyperplasia, detected by capsule endoscopy and treated via device-assisted enteroscopy.
Pouchitis
Pouchitis, also called ileal pouch inflammation, is non-specific inflammation of the ileal reservoir after ileal pouch-anal anastomosis, mainly in ulcerative colitis patients. Affects about 32% of UC pouch patients, treated with antibiotics, probiotics, and biologics.
Primary intra-abdominal hernia
Primary intra-abdominal hernia (internal hernia, ICD-11 DD50.20): congenital herniation of viscera through peritoneal or mesenteric openings inside the abdomen without surgery or trauma; paraduodenal hernias predominate, CT is first-line, strangulation risk is high.
Primary lactase deficiency
Primary lactase deficiency, also called adult-type hypolactasia or lactase nonpersistence, is the genetically programmed post-weaning decline of intestinal lactase affecting about 65-70% of adults worldwide, causing lactose malabsorption and, in roughly half of genetically predisposed people, lactose intolerance symptoms.
Primary ulcer of small intestine
Primary ulcer of small intestine (ICD-11 DA94.0, 原発性小腸潰瘍) is small bowel ulceration of unknown origin, also called simple, idiopathic, or nonspecific ulcer, including CMUSE and CNSU, presenting with anemia, bleeding, and strictures.
Proctitis
Proctitis is inflammation of the rectal mucosa within 20 cm of the anal verge, caused mainly by IBD, sexually transmitted infections, and pelvic radiation; treated by cause with antibiotics, 5-ASA, or ablation.
Protein-losing enteropathy
Protein-losing enteropathy (PLE), also called exudative enteropathy or Waldmann's disease when due to primary intestinal lymphangiectasia, is excessive loss of serum proteins into the gut, linked to over 60 conditions and diagnosed by α1-antitrypsin or 51Cr-albumin clearance.
Radiation duodenitis
Radiation duodenitis, radiation-induced duodenal inflammation, is a complication of abdominal radiotherapy, especially pancreatic SBRT; fixed retroperitoneal position raises dose, causing ulcers, bleeding, stenosis, guided by dose-volume constraints.
Radiation proctitis
Radiation proctitis, also called radiation proctopathy, is rectal mucosal injury from pelvic radiation therapy for prostate, rectal, cervical, or anal cancer; about 75% develop the acute form and roughly 1-20% the chronic bleeding form.
Radiation-induced colitis
Radiation-induced colitis (放射線誘発性大腸炎, ICD-11 DB33.41) is radiation-therapy-caused colonic mucosal inflammation, acute within 60 days or chronic after months to years, dose-dependent above roughly 45–70 Gy.
Rapunzel syndrome
Rapunzel syndrome: a rare trichobezoar (hairball) extending from the stomach through the pylorus into the small intestine, caused by trichotillomania and trichophagia, first described by Vaughan et al. in 1968, with fewer than 100 reported cases, mostly in adolescent females.
Rectal discharge
Rectal discharge (anal discharge) is any non-fecal substance, usually mucus, pus, or blood, passing from the rectum. Main causes are proctitis from STIs or IBD, hemorrhoids, radiation, and diversion; CDC regimen is ceftriaxone plus doxycycline.
Rectal foreign body
Rectal foreign body (RFB, retained anorectal foreign body): an object stuck in the rectum, usually self-inserted, requiring medical removal. Managed stepwise: transanal extraction, TAMIS or endoscopy, then milking or enterotomy; laparotomy in 8–10% of cases.
Rectal prolapse
Rectal prolapse: the rectum descends through the anus (complete or partial), mainly affecting older women, with constipation and incontinence; treated surgically by abdominal or perineal approaches, with 6-27% reported recurrence.
Rectal tenesmus
Rectal tenesmus (anal or anorectal tenesmus) is the persistent urge to pass stool despite an empty bowel, mainly from inflammatory bowel disease, proctitis, radiation, or rectal cancer, treated by addressing the underlying cause.
Refractory celiac disease
Refractory celiac disease (RCD), types I and II, persistent malabsorption and villous atrophy despite a strict gluten-free diet; type II has aberrant clonal IELs, high EATL risk, 44% 5-year survival.
Richard G. Farmer
Richard G. Farmer (Richard Gilbert Farmer, 1931–2025) was an American gastroenterologist who spent 30 years at the Cleveland Clinic and specialized in inflammatory bowel disease, publishing over 250 articles.
Second degree haemorrhoids
Second degree haemorrhoids (grade II, ICD-11 DB60.1) are internal haemorrhoids that prolapse on straining but reduce spontaneously. Treated first with fiber and lifestyle change, then rubber band ligation; recurrence is more common than after surgery but complications fewer.
Secondary lactase deficiency
Secondary lactase deficiency, or secondary lactose intolerance: loss of intestinal lactase from small bowel injury by infection (rotavirus, Giardia), celiac disease, Crohn's disease, surgery, chemotherapy, or radiation; usually reversible when the underlying cause is treated.
Short bowel syndrome
Short bowel syndrome (SBS), also called short gut, is malabsorption after loss of small intestine length from resection or disease, causing chronic intestinal failure; treated with parenteral nutrition, teduglutide, surgery, and transplantation.
Side stitch
Side stitch, or exercise-related transient abdominal pain (ETAP), is sharp, well-localized abdominal pain during exercise, most common in running and horse riding, worsened by pre-exercise eating, decreasing with age, and attributed mainly to parietal peritoneum irritation.
Slow transit constipation
Slow transit constipation (STC) is a chronic colonic motility disorder in which stool moves abnormally slowly through the colon, causing infrequent bowel movements, hard stools, and abdominal discomfort.
Small bowel atresia
Small bowel atresia, also called intestinal atresia, is a birth defect in which part of the small intestine is blocked or narrowed, causing bilious vomiting in newborns within 48 hours and treated surgically.
Small intestinal bacterial overgrowth
Small intestinal bacterial overgrowth (SIBO), also called bacterial overgrowth of the small bowel, is excessive bacteria in the small intestine causing diarrhea, bloating, and malabsorption; diagnosis by jejunal aspirate culture or breath tests is contested.
Soiling
Soiling, also called encopresis or fecal incontinence, is the passage of faeces into clothing or inappropriate places after the age of expected continence, usually from constipation with overflow leakage, treatable with laxatives and behavior modification.
Solitary rectal ulcer syndrome
Solitary rectal ulcer syndrome (SRUS), also called solitary ulcer of the rectum, is a rare benign rectal disorder from mucosal prolapse and ischemia, causing bleeding, mucus, and straining; treated with biofeedback, medication, or surgery.
Spontaneous intestinal perforation
Spontaneous intestinal perforation (SIP), also called focal intestinal perforation, is an isolated bowel perforation in extremely low-birth-weight preterm newborns, usually within 10 days of birth, distinct from NEC and treated by peritoneal drain or laparotomy.
Steatorrhea
Steatorrhea, also called fatty stool, is excess fat in stool (>7 g/day) from fat malabsorption or maldigestion. Causes include exocrine pancreatic insufficiency, celiac disease, and bile acid deficiency; diagnosed by 72-hour fecal fat testing or fecal elastase.
Stenosis of the rectum
Stenosis of the rectum (rectal stenosis, ICD-11 DB30.4) is narrowing of the rectum from malignant or benign, intrinsic or extrinsic causes; anastomotic stricture after rectal resection affects 3-20%, treated first by endoscopic balloon dilation.