Amy E. Shyer Created 2026-10-20 Updated 2026-11-05
Coauthor of research on intestinal-villus formation. The study connected growth and physical organization of intestine tissue with the emergence of a repeated folded surface.[ref]
Villification: how the gut gets its villi by Amy E. Shyer and others. Author list and described study
Ascaris lumbricoides Created 2026-10-31 Updated 2026-11-05
Ascaris lumbricoides is a large parasitic roundworm with adults in the small intestine. After ingestion of infective eggs, larvae migrate through host tissues, including the lungs, before returning to the intestine. The site of the adult therefore does not describe every developmental stage.[ref]
DPDx: Ascariasis. Life Cycle
Bile Created 2026-10-31 Updated 2026-11-05
Bile duct Created 2026-10-31 Updated 2026-11-05
Bile salt Created 2026-10-31 Updated 2026-11-05
A bile salt is an amphipathic derivative of a bile acid. Its interactions with lipids and water help solubilize otherwise poorly water-soluble material in the intestine. Recovery and reuse through enterohepatic circulation differ from the initial hepatic synthesis.
Bowel Created 2026-10-31 Updated 2026-11-05
Diarrhoea 2026-10-31
Enema Created 2026-10-31 Updated 2026-11-05
Introduction of fluid into the lower intestine for a specified diagnostic or therapeutic purpose. Mechanical evacuation of selected faecal impaction differs from a systemic treatment of the underlying cause of constipation.[ref]
Constipation by the NHS. Complications of long-term constipation
Enterohepatic circulation 2026-10-31
Recovery of substances secreted into the intestine and their return to the liver through portal venous blood; bile salt recycling is a major example.
Gastroenteritis Created 2026-10-31 Updated 2026-11-05
Inflammation of the stomach and intestines, commonly associated with diarrhea and vomiting. The syndrome can arise from different infectious and noninfectious causes, so its name does not identify one pathogen.
Gut granule Created 2026-10-20 Updated 2026-11-05
Intestinal development Created 2026-10-20 Updated 2026-11-05
Formation, regionalization and maturation of the intestine, including its epithelial surface, supporting tissues and renewing cell populations.
Intestinal obstruction Created 2026-10-31 Updated 2026-11-05
Intestinal obstruction is impairment of onward passage through the intestine. Mechanical blockage and failure of coordinated propulsion are different routes to impaired transit. Distension and upstream accumulation describe consequences, not a unique cause.
Intestinal parasite Created 2026-10-31 Updated 2026-11-05
Pancreatic acinar cell Created 2026-10-14 Updated 2026-11-05
General anasarca is extensive interstitial fluid accumulation, produced when vascular filtration exceeds the capacity of lymphatic drainage and the body's regulation of salt and water. Several mechanisms commonly act together.
Raised venous and capillary hydrostatic pressure promotes filtration. Heart failure, especially when systemic venous pressure is elevated, is a major example; renal retention of sodium and water reinforces the swelling. Severe kidney failure can itself cause general fluid overload when salt and water cannot be excreted adequately. Acute glomerulonephritis may therefore cause widespread oedema without requiring the extremely low plasma protein concentration of every nephrotic case.[ref]
Edema by Merck Manual Professional Edition. Etiology and Some Causes of Edema: cardiac, renal and hydrostatic mechanisms
Reduced plasma oncotic pressure contributes when circulating albumin is markedly depleted. Causes include heavy urinary protein loss in nephrotic syndrome, reduced synthesis in advanced liver disease, protein loss through the intestine, and severe malnutrition. In cirrhosis, altered circulation and renal salt retention add to reduced protein synthesis; the mechanism cannot be reduced to a single blocked vein. Likewise, nephrotic syndrome can include primary renal salt retention as well as a fall in oncotic pressure.[ref]
Increased vascular permeability during severe systemic inflammation, sepsis or extensive tissue injury can allow fluid and protein into the interstitium. Impaired lymphatic drainage can amplify systemic oedema, although a single obstructed lymphatic or vein ordinarily causes regional rather than general swelling. Excess administered fluid and some drugs can contribute by salt retention or altered vascular tone. Multiple mechanisms are particularly likely in a severely ill patient.
A nineteenth-century description would group much of this as cardiac, renal or hepatic “dropsy,” and might invoke an impoverished state of the blood. Modern physiology specifies the abnormalities that those broad descriptions leave unresolved. A general examination should distinguish pitting fluid accumulation from a predominantly non-pitting disorder such as myxoedema, and from isolated ascites. The distribution, jugular venous filling, heart and lung findings, urinary albumin, renal function and plasma albumin help distinguish causes. Anasarca is a sign with several possible causes, not a diagnosis of renal disease by itself.
Abdominal hernias are classified primarily by the opening through which tissue protrudes; groin and scrotal swellings have a substantially wider differential diagnosis. Reducibility, obstruction and strangulation describe the state of a hernia, rather than different anatomical sites.
The principal external varieties are indirect inguinal hernia and direct inguinal hernia, femoral hernia, umbilical hernia and other anterior abdominal-wall hernias, including epigastric hernia and incisional hernia. An indirect inguinal hernia enters through the deep inguinal ring lateral to the inferior epigastric vessels and can follow the canal into the scrotum; a direct inguinal hernia passes through the posterior wall medial to those vessels. A femoral hernia passes through the femoral canal below the inguinal ligament, rather than along the inguinal canal.[ref]
Surgical Mesh Used for Hernia Repair by the FDA. Types of hernia: inguinal, femoral, incisional, ventral, umbilical and hiatal
Less common wall or pelvic varieties include lateral ventral hernia, lumbar hernia, obturator hernia, sciatic hernia and perineal hernia. Diaphragmatic hernia defects allow abdominal contents into the thorax. Internal hernias can pass through a mesenteric or peritoneal aperture while remaining within the abdominal cavity, including paraduodenal recesses or the epiploic foramen. Contents may be intestine, omentum or other viscera; a developmental route and an acquired wall weakness can yield different forms at the same broad site.[ref]
Hernias of the Abdominal Wall by Merck Manual Professional Edition. Anatomical varieties and distinction of inguinal and femoral defects
[ref]Internal Hernias: A Difficult Diagnostic Challenge. Review of CT Signs and Clinical Findings. Classification by aperture and internal location
In the groin, alternatives to an inguinoscrotal hernia include enlarged or inflamed lymph nodes, an abscess, lipoma of the spermatic cord or other soft tissue, a retained or undescended testis, a hydrocele of the cord, a saphena varix, and a femoral aneurysm or pseudoaneurysm. A femoral hernia is also an important separate diagnosis. A fluid collection along a persistent female inguinal peritoneal process can produce a corresponding inguinal swelling. These lesions are not interchangeable merely because they lie near the inguinal opening.[ref]
Inguinal Hernias: Diagnosis and Management by the American Academy of Family Physicians. Differential diagnosis of groin swelling
In the scrotum, consider hydrocele, haematocele, spermatocele or an epididymal cyst, varicocele, epididymitis, orchitis, abscess, traumatic swelling and a testicular tumour. Torsion of the testis or its appendages can cause acute painful swelling. General oedema or lymphoedema can enlarge the scrotal wall diffusely rather than create one discrete lump.[ref]
Painless Scrotal Mass by Merck Manual Professional Edition. Etiology: hydrocele, varicocele, cystic masses, haematocele, oedema and tumour
[ref]The Acute Scrotum by the American Urological Association. Differential diagnosis: torsion, trauma, infection and other acute swelling
The discriminating examination locates the swelling relative to the inguinal ligament and to the testis, asks whether it is cystic or solid, and notes posture-related change, reducibility, cough impulse and transillumination when relevant. A cough impulse is not exclusive to a hernia; a communicating fluid collection or a venous swelling may vary with pressure. Modern ultrasonography, including assessment of blood flow when indicated, can clarify uncertain anatomy. The site and character of a swelling must be established before it is called an inguinoscrotal hernia.
The four agents have different proposed purposes. Their indications must be tied to a mechanism and a diagnosis, and their historical use must not be converted into a general modern recommendation. In particular, a historical effect on a discharge, pulse or bowel movement is not proof of cure of the disease causing it.
Elaterium was a drastic hydragogue purgative, the dried deposit from the juice of squirting cucumber fruit. The intended use was to remove fluid through the intestine in severe dropsy, particularly some cardiac cases. The same action explains the danger: violent diarrhoea, abdominal irritation, dehydration and collapse. Frailty, existing fluid depletion, inflammatory disease of the intestine, suspected bowel obstruction and pregnancy make such treatment particularly objectionable. Variable potency further undermines a fixed-dose rule.[ref]
The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Cucurbitaceae, Elaterium: preparation, hydragogue action, dropsy and irritant effects
In current care, identify the cause of oedema; cardiac fluid overload may require monitored diuretic treatment, not deliberate drastic purging. Elaterium is not a substitute for a modern diuretic.Digitalis preparations, historically obtained from foxglove leaves, were used to slow and strengthen cardiac action and promote diuresis in selected forms of cardiac dropsy. An appropriate indication therefore requires assessment of the heart and circulation, not the mere presence of swelling. Modern digoxin is a standardised cardiac glycoside, used in selected heart failure and atrial fibrillation; it is not equivalent to an arbitrary amount of crude leaf. Important contraindications include certain atrioventricular blocks, ventricular tachycardia, ventricular fibrillation and particular accessory-pathway arrhythmias. Renal impairment, hypokalaemia and interacting medicines increase the risk of toxicity and demand attention to dosing and monitoring. A very slow pulse, new cardiac arrhythmia, nausea or visual disturbance during treatment calls for assessment, not additional doses to obtain more diuresis.[ref]
Digoxin tablets summary of product characteristics (emc). §§4.1–4.5: indications, conduction disease, arrhythmias, renal function, electrolytes and interactions
Aloes means the dried aloe leaf juice used as a stimulant laxative, not the relatively different leaf gel. Historically it was used for sluggish bowel action and sometimes as an emmenagogue, on theories of pelvic stimulation. The latter is not a present treatment for an unexplained absent period. The recognised current herbal indication is short-term occasional constipation, with limits on duration and age. Contraindications include bowel obstruction, inflammatory bowel disease, unexplained abdominal pain, severe dehydration, pregnancy and breastfeeding. Repeated purgation can disturb water and electrolyte balance; constipation caused by a serious obstruction should not be treated by progressively stronger laxatives.[ref]
Aloes folii succus siccatus by the European Medicines Agency. Public summary: dried leaf juice, short-term use and contraindications
Copaiba is an oleoresin, historically given for gonorrhoea and persistent urethral discharge, and sometimes other mucosal complaints. Period selection tended to favour a less acutely inflamed stage; irritation of the stomach and urinary tract, nausea, diarrhoea or a rash argued against continuing it. The contemporary monograph also warns against its use in febrile states. Existing marked urinary irritation is poor ground for an irritant empirical remedy.[ref]
The Essentials of Materia Medica and Therapeutics by Alfred Baring Garrod (1865). Cisalpinae, Copaiba: balsam and oil, urinary uses and unwanted effects
Modern gonorrhoea requires appropriate microbiological diagnosis, effective antibiotic treatment and partner management. Current CDC guidance uses ceftriaxone-based treatment; copaiba is not an alternative to eradication of the infection. Apparent reduction of discharge cannot establish microbiological cure.[ref]Gonococcal infections among adolescents and adults by CDC. Diagnostic considerations, recommended regimens and management of partners
Thus the period shorthand is fluid removal by elaterium, selected cardiac treatment by digitalis preparations, bowel stimulation by aloes, and a disputed treatment of mucosal discharge by copaiba. Present interpretation preserves the useful distinction between actions while rejecting the assumption that all four historical indications remain valid.
Tapping must follow identification of the fluid-containing cavity: abdominal paracentesis for ascites, thoracentesis for a pleural effusion. An enlarged abdomen or a dull area of chest is not, by itself, a sufficient indication for blind puncture. The object may be relief of pressure or obtaining fluid for diagnosis; neither necessarily removes the underlying cause.
Abdomen: states in which tapping is useful. Tense or troublesome ascites can interfere with breathing, eating and comfort, particularly when it persists despite treatment of its cause. Causes include cirrhosis with portal hypertension, heart failure, malignant peritoneal disease and some inflammatory or infective conditions. New or unexplained ascites can also require diagnostic sampling. General swelling without a drainable peritoneal collection is a different problem. An ovarian cyst, a gravid uterus, a distended urinary bladder and gaseous distension must not be mistaken for free ascites. [ref]
Guidelines on the Management of Ascites by the BSG and BASL. Diagnostic paracentesis and large-volume paracentesis
[ref]Ascites Practice Guidance by AASLD (2021). Initial diagnosis: cirrhosis and alternative causes, imaging and diagnostic paracentesis
Abdomen: operative account. The characteristic historical apparatus is a sharp trocar within a hollow cannula. The patient is supported, the presence and distribution of fluid established, and the urinary bladder emptied to keep it away from the lower abdominal puncture route. Traditional descriptions use an appropriate abdominal site, often in the midline below the umbilicus; a landmark is not sufficient if an enlarged organ, a vessel or adherent intestine is in the way. Once the instrument has entered fluid, withdrawal of the trocar leaves the cannula as the drainage channel. The patient and the flow are observed, and the opening is dressed after removal. This describes the operation's principle, not a universally safe blind puncture point.
Modern performance uses sterile preparation, appropriate local anaesthesia, a selected fluid pocket and a catheter system rather than assuming that every distended abdomen can be tapped in the same place. Ultrasound helps identify a safe pocket and avoid organs and vessels. Samples may be sent for cell counts, protein and albumin measurements, culture or cytology according to the clinical question. Therapeutic drainage requires reassessment because haemorrhage, intestinal injury, leakage, infection and circulatory or renal disturbance can occur. In cirrhotic large-volume drainage, albumin replacement has a specific modern role; it is not an 1865 routine to be projected backwards. [ref]
Guidelines on the Management of Ascites by the BSG and BASL. Recommendations 1–2 and 5–6: fluid assessment, ultrasound guidance, drainage and albumin
Thorax: states in which tapping is useful. A large pleural effusion producing respiratory difficulty can be relieved, and an unexplained effusion can be sampled to identify its cause. Serous fluid, blood and pus have different implications: pleural effusion associated with heart failure, malignant disease or inflammation is not identical to empyema. A purulent collection may require continuing drainage and treatment of the infection, not merely one palliative aspiration. Contemporary experience already included tapping in hydrothorax; an 1864 report with subsequent anatomical examination illustrates how removal of fluid could coexist with serious underlying disease. [ref]
Paracentesis report in the Medical Society of the County of Kings (1864). Opening report: hydrothorax, thoracic paracentesis, subsequent death and anatomical examination
Thorax: operative account. The supported position exposes a suitable part of the chest; the operator first distinguishes fluid from consolidated lung and identifies its upper extent and the diaphragm. An appropriate intercostal route enters the fluid above a rib, avoiding the principal vessels and nerve running along its lower border. The drainage apparatus should permit controlled outflow without freely introducing air. The position of the lung, diaphragm, liver and spleen makes an arbitrarily low puncture unsafe. Historic trocar-and-cannula entry and modern small catheter aspiration share the need to enter the collection without injuring these structures.
Current guidance requires thoracic ultrasound for aspiration of a pleural effusion, a suitable needle or catheter, and slow controlled drainage. Chest tightness, pain, persistent cough or increasing breathlessness are reasons to stop and reassess, not simply to continue until no more fluid runs. Complications include pneumothorax, haemorrhage, injury to an abdominal organ, infection and re-expansion pulmonary oedema. These precautions belong to current practice; they must not be represented as technology available in 1865. [ref]
Pleural Procedures by the British Thoracic Society (2023). Pleural aspiration: ultrasound, entry above a rib, controlled drainage and stopping symptoms
The principal intestinal Entozoa to describe are roundworms, threadworms, whipworms and tapeworms; the chief visceral larval form is the hydatid. “In this country” refers to the British setting of the paper. It is not a claim that all human helminths were common or acquired locally. A contemporary account already distinguished Nematoda, Cestoda and Trematoda, and recognised that an adult worm and a larval cyst could be different phases of one life cycle.[ref]
Entozoa, an Introduction to the Study of Helminthology by Thomas Spencer Cobbold. 1864; systematic treatments of human nematodes, cestodes and trematodes
The life cycles below use present knowledge to explain transmission; their inclusion does not imply that every migratory stage or intermediate host was established in 1865.Ascaris lumbricoides lives as a large, cylindrical, unsegmented, tapering roundworm in the small intestine; adults are cream-coloured or pinkish and roughly 15–35 cm long, with the male generally smaller and its tail curved. Eggs leave in faeces and become infective after development in the environment. After ingestion, larvae cross the intestinal wall, pass through the liver and lungs, ascend the airway, are swallowed and mature in the small intestine. Adults can wander into the bile ducts. The pulmonary migration belongs to the larval history, not to the usual location of the adult.[ref]
DPDx: Ascariasis. Life cycle; adult morphology
Enterobius vermicularis, the threadworm, is a small white nematode of the caecal and adjacent colonic region. The female is about 8–13 mm long and has a conspicuous pointed tail; the male is shorter. The gravid female migrates to the perianal skin and deposits eggs, often at night, so itching and transfer by contaminated fingers favour renewed infection. Eggs become infective rapidly; a pulmonary migration is not part of its usual life cycle. This explains why a perianal adhesive sample can be more useful than an ordinary stool examination.[ref]
DPDx: Enterobiasis. Life cycle; adult worms; diagnostic findings
Trichuris trichiura, historically Trichocephalus dispar, inhabits the caecum and colon. The adult is about 3–5 cm long, with a very slender anterior portion embedded in the mucous membrane and a thicker posterior portion projecting into the lumen: the outline resembles a whip. Eggs pass in faeces, mature in soil and infect after ingestion. The adult shape and the characteristic eggs with polar plugs distinguish it from the preceding worms.[ref]
DPDx: Trichuriasis. Life cycle and morphology
Adult Taenia are flat, ribbon-like tapeworms, several metres long, with a small attachment head or scolex, a narrow neck and a chain of proglottids. Taenia solium has four suckers and a hooked rostellum; Taenia saginata, also called Taenia mediocanellata in period literature, has four suckers but lacks that crown of hooks. Their larval cysticerci occur in pig and cattle tissues respectively; ingestion of inadequately cooked infected meat permits an adult to develop in the human small intestine. Eggs and segments pass in faeces. Egg appearance alone does not reliably distinguish these two species.[ref]
For Taenia solium, swallowing eggs is a different event from swallowing pork cysticerci: eggs can establish tissue cysticercosis in humans, including abdominal tissues, whereas pork larvae cause intestinal taeniasis. A cysticercus is a small fluid-filled bladder with an invaginated scolex, not a miniature chain of segments.[ref]
DPDx: Cysticercosis. Life cycle and tissue cyst morphology
The hydatid of Echinococcus granulosus is particularly important in the liver. Humans acquire eggs from contamination associated with infected dogs and act as intermediate hosts. Larvae reach viscera and form a fluid-filled cyst with a laminated wall and an inner germinal layer; brood capsules, protoscolices and sometimes daughter cysts develop inside. The tiny adult tapeworm belongs in the dog's intestine, not as the normal human liver worm. Dogs complete the cycle by eating infected viscera from an intermediate host.[ref]
Less usual examples deserve proportionate mention. Diphyllobothrium latum is a broad, segmented fish tapeworm with two longitudinal attachment grooves rather than four suckers; aquatic intermediate hosts and infected fish link it to humans. It should not be presented as a uniformly common British infection.[ref]
DPDx: Diphyllobothriasis. Life cycle; adult morphology
Fasciola hepatica, a leaf-shaped fluke roughly 2–3 cm long with oral and ventral suckers, can inhabit the bile ducts; its cycle requires a freshwater snail and infective stages on aquatic vegetation. Human disease was an unusual counterpart of an important infection of grazing animals.[ref]DPDx: Fascioliasis. Life cycle and adult morphology
Trichinella spiralis has minute intestinal adults after ingestion of infected meat, but its enduring encysted larvae occupy skeletal muscle; those muscle cysts should not be misdescribed as the typical abdominal hydatid.[ref]Gross form and location guide identification, but microscopy of eggs, larvae or segments and knowledge of the life cycle supply the confirmation.