196 articles
Laceration of duodenum
Laceration of duodenum (十二指腸裂創), a traumatic tear of the duodenal wall graded I to V on the AAST scale and WSES classes I to IV; rare, retroperitoneal, diagnosed by CT, treated by primary repair or damage control surgery.
Left sided ulcerative colitis
Left-sided ulcerative colitis (Montreal E2) is UC limited to the colon distal to the splenic flexure, about 40% of cases at diagnosis, treated first with combined rectal and oral 5-aminosalicylates.
Lymphocytic colitis
Lymphocytic colitis, a subtype of microscopic colitis with collagenous colitis, causes chronic watery diarrhea with a normal-appearing colon; diagnosis requires biopsies showing ≥20 intraepithelial lymphocytes per 100 enterocytes, and budesonide is first-line treatment.
Lymphoid polyp
Lymphoid polyp (lymphoid hyperplasia, benign lymphoma): a benign polyp of well-differentiated lymphoid tissue, typically in the terminal ileum or rectum, self-limiting and often mimicking carcinoid or lymphoma.
Malabsorption
Malabsorption, also called malabsorption syndrome, is impaired assimilation of dietary nutrients due to defects in digestion, absorption, or transport, causing diarrhea, weight loss, and nutritional deficiencies.
Meckel's diverticulum
Meckel's diverticulum, a true ileal diverticulum from vitelline duct persistence, affects 1–3% of people; ectopic gastric mucosa causes bleeding, obstruction, or diverticulitis, diagnosed by Tc-99m scan and treated by resection.
Meconium ileus with perforation
Meconium ileus with perforation (ICD-11 KB87.4) is complicated neonatal ileus where thick meconium obstructs the distal ileum and the bowel ruptures, causing meconium peritonitis; usually linked to cystic fibrosis and treated surgically.
Megacolon
Megacolon is abnormal dilatation of the colon, also called congenital megacolon in Hirschsprung disease. Covers toxic megacolon (>6 cm dilation with systemic toxicity), Ogilvie syndrome, and acquired idiopathic megacolon.
Megacystis-microcolon-intestinal hypoperistalsis syndrome
MMIHS, or Berdon syndrome, is a rare congenital smooth muscle disorder causing megacystis, microcolon, and absent intestinal peristalsis, usually from autosomal dominant de novo ACTG2 mutations, managed with parenteral nutrition and transplantation.
Megaloappendix
Megaloappendix (ICD-11 DB11.0) is an abnormally long, enlarged vermiform appendix; the largest removed measured 55 cm in a 2011 Qatari case report, versus a 6–9 cm normal average.
Melena
Melena is black, tarry, foul-smelling stool from gastrointestinal bleeding, usually upper GI (stomach, duodenum); hematin from digested blood colors it, over 100 mL blood makes one stool, and iron or bismuth can mimic it.
Microscopic colitis
Microscopic colitis (collagenous colitis, lymphocytic colitis) is a chronic inflammatory bowel disease causing watery diarrhea with normal colonoscopy, diagnosed by biopsy histology; budesonide is first-line therapy.
Mucocele of appendix
Mucocele of appendix (appendiceal mucocele): mucin-filled cystic dilatation of the appendix, a descriptive term covering retention cysts through LAMN, HAMN, and mucinous adenocarcinoma; rupture risks pseudomyxoma peritonei; treated by appendectomy guided by pathology.
Necrotizing enterocolitis
Necrotizing enterocolitis (NEC) is inflammatory bowel necrosis mainly in preterm, very low birth weight infants; incidence up to 22% under 1,000 g, mortality about 25% (35% surgical), driven by dysbiosis, immaturity, and feeding.
Non-celiac gluten sensitivity
Non-celiac gluten sensitivity (NCGS, also non-celiac gluten/wheat sensitivity, NCGWS): intestinal and extraintestinal symptoms from gluten-containing foods without celiac disease or wheat allergy; fructans may trigger symptoms more than gluten.
Non-occlusive mesenteric ischaemia
Non-occlusive mesenteric ischaemia (NOMI), also nonocclusive mesenteric ischemia, is intestinal ischemia without mesenteric vessel obstruction, caused by low-flow states and vasospasm; treated with resuscitation, intra-arterial vasodilators, and surgery.
Nonspecific mesenteric lymphadenitis
Nonspecific mesenteric lymphadenitis, also called primary mesenteric adenitis, is a self-limiting inflammation of the abdominal lymph nodes draining the intestine that mainly affects children and mimics appendicitis.
Obscure gastrointestinal bleeding
Obscure gastrointestinal bleeding (OGIB) is bleeding from the digestive tract with no source found after negative endoscopy; it may be visible or hidden, such as iron-deficiency anemia.
Obstruction of duodenum
Obstruction of the duodenum, or duodenal obstruction, is a partial or complete blockage of the first part of the small intestine, common in newborns with duodenal atresia.
Obstruction of large intestine
Obstruction of large intestine (large bowel obstruction, LBO): blockage of colon or rectum, 20–25% of bowel obstructions. Main causes colorectal cancer (50–60%), volvulus, diverticular strictures; CT is definitive imaging; mortality 9.8–20%.
Obstruction of small intestine
Obstruction of small intestine (ICD-11 DA91): blockage of luminal flow in the small bowel, partial or complete, simple or strangulating. Main causes are adhesions, hernias, and malignancy; CT is the diagnostic standard, and management ranges from decompression to surgery.
Ogilvie syndrome
Ogilvie syndrome, or acute colonic pseudo-obstruction, is massive colonic dilatation without mechanical obstruction, first described by Sir Heneage Ogilvie in 1948; treated with supportive care, neostigmine, or colonoscopy.
Parastomal hernia
Parastomal hernia (PSH): an incisional hernia at a colostomy, ileostomy, or ileal conduit stoma site; incidence 28–48%, risk factors include BMI, age, female sex, aperture size; mesh repair preferred over suture repair.
Pelvic hernia
Pelvic hernia (ICD-11 DD50.1): hernia through a foramen in the pelvic wall, including obturator, sciatic, perineal, and pudendal hernia; rare, mostly in elderly women, diagnosed by CT and treated surgically.
Perforation of duodenum
Perforation of duodenum: transmural duodenal wall injury, also called duodenal perforation. Main causes are peptic ulcer (H. pylori, NSAIDs), ERCP and other iatrogenic injury, and trauma; mortality 8-25%, higher with peritonitis.
Perforation of large intestine
Perforation of large intestine is a complete breach of the colonic wall that leaks bowel contents into the abdomen, causing peritonitis; common causes include cancer, diverticulitis, and colonoscopy injury.
Perforation of small intestine
Perforation of small intestine (ICD-11 ME24.30), also called non-traumatic small bowel perforation: full-thickness breach of the jejunal or ileal wall leaking contents into the abdomen, causing peritonitis; causes include iatrogenic injury, ischemia, malignancy, Crohn disease, and trauma.
Perirectal abscess
Perirectal (perianal, anorectal) abscess: pus collection near the anus, usually cryptoglandular. Treated by incision and drainage; antibiotics and packing have limited roles; fistula follows in a third to half.
Pneumoperitoneum
Pneumoperitoneum is free gas in the peritoneal cavity, usually signaling perforated viscus (90% of non-postoperative cases), common and often benign after abdominal surgery, and deliberately created with CO2 insufflation for laparoscopy.
Polyp (medicine)
Polyp (medicine): abnormal tissue growth projecting from a mucous membrane into a hollow organ (colon, uterus, stomach); sessile or pedunculated, mostly benign, removed by polypectomy, with adenomas carrying colorectal cancer risk.