196 articles
Abdominal distension
Abdominal distension is a measurable increase in abdominal girth, distinct from bloating, a subjective sensation of fullness or trapped gas. Mainly caused by abdomino-phrenic dyssynergia rather than excess gas; managed with diet, drugs, and biofeedback.
Acute haemorrhagic rectal ulcer
Acute hemorrhagic rectal ulcer (AHRU, AHRUS), term coined by Soeno 1981 in Japan; sudden painless massive rectal bleeding from distal rectal ulcers near the dentate line in elderly bedridden patients with serious comorbidities.
Acute vascular disorders of intestine
Acute vascular disorders of intestine (ICD-11 DD30) is a diagnostic category covering acute intestinal ischemia, where inadequate blood flow to the bowel can be fatal without treatment.
Anal fissure
Anal fissure (fissure-in-ano), a painful longitudinal tear in the anal lining, most often posterior midline, caused by hard stools and sphincter hypertonia; treated with sitz baths, topical nitrates or calcium channel blockers, botulinum toxin, or lateral internal sphincterotomy.
Anal fistula
An anal fistula, also called fistula in ano, is an abnormal channel between the anal canal and nearby skin, usually after an anal abscess, and rarely heals without surgery.
Anal polyp
Anal polyp (ICD-11 DB71, ICD-10 K62.0), also called anal canal polyp or anal papilla, is a descriptive term for benign intraluminal anal canal growths: hyperplastic, fibroepithelial, cloacogenic, adenoma, hypertrophied papilla; treated by excision with histology.
Angiodysplasia of colon
Angiodysplasia of the colon (colonic angioectasia, vascular ectasia): degenerative right-colon vascular malformation causing lower GI bleeding and anemia, mainly over age 60; diagnosed by colonoscopy, treated with argon plasma coagulation.
Anorectal abscess
Anorectal abscess, a pus collection around the anus from blocked anal glands (cryptoglandular origin), treated by incision and drainage; recurrence up to 44% and fistula-in-ano in about 15% of patients.
Appendicitis
Appendicitis, inflammation of the appendix (vermiform appendix), the most common abdominal surgical emergency; treated by laparoscopic appendectomy or, in selected uncomplicated cases, antibiotics, with APPAC and CODA trial outcomes.
Appendicular concretions
Appendicular concretions (appendicoliths, fecaliths; ICD-11 DB11.2, ICD-10 K38.1) are calcified fecal stones in the appendix lumen, found in roughly 40% of appendicitis CT scans, linked to complicated appendicitis and antibiotic-treatment failure, but often incidental.
Auto-brewery syndrome
Auto-brewery syndrome, or gut fermentation syndrome, is a rare disorder in which gut bacteria or yeasts such as Saccharomyces and Candida ferment dietary carbohydrates into ethanol, causing intoxication without drinking; diagnosed by carbohydrate challenge, treated with diet and antifungals.
Baby colic
Baby colic (infantile colic) is excessive, unexplained crying in healthy infants under 5 months, defined by Wessel's rule of threes and Rome IV criteria; it resolves by 3-4 months, and probiotics show modest benefit mainly in breastfed babies.
Benign neoplasm of duodenum
Benign neoplasm of duodenum (ICD-11 2E92.2; ICD-10 D13.2): noncancerous duodenal tumors, mainly adenomas, lipomas, leiomyomas, and Brunner gland lesions; 10–20% of duodenal tumors, managed by endoscopic resection.
Bile acid malabsorption
Bile acid malabsorption (BAM, bile acid diarrhea/BAD): chronic watery diarrhea from excess colonic bile acids due to ileal reabsorption failure or excess synthesis; types 1–3; diagnosed by SeHCAT, serum C4, FGF19; treated with bile acid sequestrants.
Bloating
Bloating: uncomfortable abdominal fullness or pressure, distinct from visible distension. Common causes include gut gas from FODMAPs, constipation, IBS, SIBO, and visceral hypersensitivity; low FODMAP diet is the best-supported therapy.
Blood in stool
Blood in stool (rectal bleeding, hematochezia, melena): visible GI bleeding from hemorrhoids, fissures, diverticula, polyps, IBD, or colorectal cancer; color and pattern hint at the bleeding source.
Bowel obstruction
Bowel obstruction, also called intestinal obstruction, is a mechanical blockage of intestinal contents, usually from adhesions, hernias, or tumors; strangulation threatens bowel viability, and treatment combines resuscitation, decompression, and selective surgery.
Bristol stool scale
Bristol stool scale (Bristol Stool Form Scale, BSFS): seven-type medical tool classifying human feces from type 1 hard lumps to type 7 watery diarrhea; types 3-5 normal; developed at Bristol Royal Infirmary, validated for transit time by Lewis and Heaton in 1997.
Cap polyposis
Cap polyposis is a rare, benign colorectal condition in which inflammatory polyps covered by a white cap arise mainly in the rectum, causing rectal bleeding and altered bowel habits.
Change in bowel habit
Change in bowel habit (altered bowel habit): any alteration in stool frequency, consistency, or form; ICD-11 ME05, ICD-10 R19.4. Cardinal IBS symptom and colorectal cancer red flag prompting FIT and calprotectin testing.
Chronic appendicitis
Chronic appendicitis (ICD-11 DB10.1; grumbling or recurrent appendicitis) is a non-acute, prolonged inflammation of the appendix causing persistent right lower quadrant pain, diagnosed by history, deep palpation, histology, and relief after appendectomy.
Chronic diarrhea due to glucoamylase deficiency
Chronic diarrhea due to glucoamylase deficiency, also called maltase-glucoamylase deficiency (ORPHA:103907, ICD-11 5C61.1), is a rare intestinal disease of infancy or childhood: primary small-intestinal glucoamylase deficiency impairs starch absorption, causing chronic diarrhea with normal pancreatic amylase and normal mucosal histology.
Chronic enteropathy associated with SLCO2A1 gene
Chronic enteropathy associated with SLCO2A1 gene (CEAS), formerly CNSU, is a rare autosomal recessive small-intestinal ulcer disease from SLCO2A1 prostaglandin transporter mutations, mimicking Crohn's disease, with female predominance, anemia, and ileal ulcers.
Chronic intestinal failure
Chronic intestinal failure (CIF, type 3 intestinal failure): persistent loss of gut absorptive function requiring long-term intravenous supplementation, usually home parenteral nutrition. Main cause short bowel syndrome; treatments include teduglutide and intestinal transplantation.
Chronic intestinal pseudoobstruction syndrome
Chronic intestinal pseudoobstruction syndrome (CIPO, CIPS) is a rare severe gastrointestinal motility disorder mimicking mechanical bowel obstruction without occlusive lesion, treated with nutrition support, prokinetics, and sometimes transplant.
Chylomicron retention disease
Chylomicron retention disease (Anderson disease, CMRD) is a rare autosomal recessive fat-malabsorption disorder caused by biallelic SAR1B mutations blocking COPII chylomicron secretion, presenting in infancy with failure to thrive, steatorrhea, and hypocholesterolemia with normal triglycerides.
Ciguatera fish poisoning
Ciguatera fish poisoning (CFP), ciguatera, is seafood poisoning from ciguatoxins made by Gambierdiscus dinoflagellates and concentrated in large reef fish; 10,000–50,000 cases yearly, temperature reversal hallmark, fatality under 0.1%.
Coeliac disease
Coeliac disease (celiac disease, gluten-sensitive enteropathy) is a chronic autoimmune disorder triggered by gluten in wheat, barley, and rye, damaging the small intestine in about 1% of people; treated with a lifelong gluten-free diet.
Colectomy
Colectomy is surgery removing part or all of the colon, also called colon resection or bowel resection. Types include hemicolectomy, proctocolectomy, and sigmoidectomy; done open, laparoscopically, or robotically for cancer, diverticulitis, and IBD.
Colitis
Colitis is inflammation of the colon (large intestine), with infectious, ischemic, microscopic, radiation, and IBD forms such as ulcerative colitis and Crohn's disease; symptoms include bloody diarrhea, and treatment depends on cause.