GI Pathology (10.1 - 10.6) Flashcards
What is the cause of cleft lips/ palate?
failure of the facial prominences to fuse
True or false: cleft lip and palate usually occur together
True
How do the pharyngeal arches fuse in development?
Come from all directions to fuse together to form the mouth
Superficial ulcerations of the oral mucosa = ?
Aphthous ulcer
What are the gross characteristics of aphthous ulcers?
Grayish base surrounded by erythema (granulation tissue)
What is Behcet syndrome? What causes it? What is the classic triad of symptoms?
Recurrent aphthous ulcers, genital ulcers, and uveitis caused by immune complex vasculitis of small vessels
When do the symptoms of Behcet syndrome usually recur?
After viral infection
What is the virus that usually causes oral herpes?
HSV-1
What are the gross characteristics of oral herpes?
Shallow, painful red ulcers or vesicles on the lips
When in life does HSV-1 infection usually occur? Where does it lie dormant?
Early in childhood, and remains dormant in the ganglia in the trigeminal nerve
What causes the reactivation of the HSV-1 virus?
Stress and sunlight
What is the most common location of SCC in the mouth?
Floor of the mouth
What are the risk factors for developing SCC in the mouth?
EtOH and Tobacco
What are the precursor lesions to SCC in the oral cavity?
Leukoplakia or erythroplakia
What is the risk of leukoplakia/erythroplakia?
Progression to SCC
What are the diseases that should be in your differential when you see white plaques in the oral cavity? How do you differentiate?
Oral candidiasis
Hairy Leukoplakia
Leukoplakia
Scrape it off (candida if it comes off)
Where is hairy leukoplakia usually found? What virus causes this?
Lateral aspect of the tongue
EBV
What are the two major differences between oral hairy leukoplakia, and leukoplakia of SCC?
Oral hairy leukoplakia is caused by EBV, and is only hyperplasia of the tongue cells
SCC leukoplakia is dysplasia
—-What is erythroplakia? What does this suggest?—-
—-Leukoplakia that is vascularized
this suggests squamous dysplasia—–
What are the three major salivary glands in the mouth?
- Parotid
- Submandibular
- Sublingual
What is the most feared complication of mumps? Why?
Sterility secondary to testicular infection
What is the virus that causes mumps? Family?
- Mumps virus
- Paramyxovirus
What are the two causes of increased serum amylase in Mumps?
Increased production from BOTH the salivary gland, and pancreas
What GI organ can be affected with Mumps? What does it cause?
Pancreatitis
What are the neurological concerns with Mumps?
Meningitis
What is sialadenitis? What is the usual cause? What is the feared complication of this?
Inflammation of the salivary gland usually secondary to sialolithiasis and subsequent Staph. Aureus infection
True or false: Sialadenitis is usually bilateral
False- usually unilateral
What is pleomorphic adenoma? What are the tissue types that compose this?
Benign salivary gland tumor composed of stromal and epithelial tissue
Where do pleomorphic adenoma usually occur?
Parotid gland
What are the s/sx of pleomorphic adenomas?
Mobile, painless circumscribed mass at the angle of the jaw
What nerve is at risk with parotid gland tumors?
Facial nerve issues
Why is there a high rate of recurrence of pleomorphic adenomas?
Very irregular margins, thus may lead to leaving in cells during a surgery
What is a Warthin tumor? Histological characteristic?
Benign cystic tumor with abundant lymphocytes and germinal centers
Where do Warthin tumors usually arise? Why?
Parotid glands–one of the last glands in development to separate from adjacent lymph node tissues
What are the benign tumors of the parotid gland? (3)
- Pleomorphic adenomas
- Warthin tumors
- Mucoepidermoid carcinoma
What is the most common malignant tumor of the parotid gland?
Mucoepidermoid carcinoma
—–What are mucoepidermoid carcinomas? What type of cells compose it? Where is it usually found?—–
—–Malignant tumor composed of mucinous and squamous cells that usually arises in the parotid gland—–
What is the most common congenital defect of the esophagus?
Atresia of the esophagus, with a fistula between the distal esophagus and the trachea
What are the signs of esophageal atresia in utero (1), and when born (2)?
- Polyhydramnios
- Abdominal distention
- Aspiration
What are esophageal webs? What layer of the esophagus is involved, and where in the esophagus do these usually occr?
Thin protrusion of esophageal mucosa, most often in the upper esophagus
What are the signs of esophageal webs? What cancer are these patients predisposed to?
- Dysphagia for poorly chewed foods
- SCC
What causes the abdominal distention and aspiration with esophageal atresia?
-Air going into the stomach causes distention, with resulting regurgitation going into the trachea and lungs
What are the four layers of the GI tract?
- Mucosa
- Submucosa
- Muscularis propria
- Serosa
What is the most common complication of esophageal webs?
Plummer-Vinson syndrome
What is Plummer-Vinson syndrome? What is the classic triad of symptoms?
Severe Fe deficiency anemia presenting with:
- beefy red tongue
- dysphagia
- Fe deficiency anemia
What is a Zenker diverticulum? Where does this usually occur?
Out pouching of pharyngeal mucosa through an acquired defect in the muscular wall, arising above the upper esophageal sphincter at the junction of the esophagus and pharynx
What are the s/sx of a Zenker diverticulum? (3)
- Dysphagia
- obstruction
- halitosis
What layers of the GI tract are involved in a Zenker diverticulum? Is this a true diverticulum?
Pharyngeal mucosa and submucosa–no, since it does not involve the muscularis externa
What is Mallory-Weiss syndrome? Cause?
Longitudinal laceration of the mucosa at the gastroesophageal junction, d/t excessive vomiting (alcoholism, and bulimia)
What are the s/sx of Mallory-Weiss syndrome?
Painful hematemesis
What disease can Mallory-Weiss syndrome progress to?
Boerhaave syndrome
What is Boerhaave syndrome?
Rupture of the esophagus, causing air in the mediastinum and subcutaneous emphysema of the neck
What is the cause of esophageal varices?
Portal HTN
What are the two veins that the esophageal vessels drain into?
- Azygos vein into the SVC
- Left gastric into the hepatic portal
What is the cause of painful hematemesis? Painless?
Painful = Mallory-Weiss syndrome
Painless = esophageal varices
What are the two major reasons esophageal varices 2/2 portal HTN results in profuse hemorrhaging?
- Increased probability of rupture
- Lower coag factors d/t cirrhosis
What is achalasia? What is the cause of this?
- Disordered esophageal motility with inability to relax LES
- Due to damaged ganglion cells in the myenteric nerve plexus
What parasitic infection can lead to achalasia of the esophagus?
Chagas disease
What are the s/sx of achalasia (2)? Imaging findings?
- Inability to swallow solid and liquids
- Halitosis
- “Bird Beak” sign of the esophagus on Ba swallow
What is the plexus of nerves that runs between the inner circular layer, and outer longitudinal layer of the GI tract? What is the function of this plexus?
- Myenteric
- Controls muscle motility
What neoplastic process can achalasia progress to?
esophageal SCC
What is the relative pressure of the LES in achalasia (high or low)?
High
What is the change in the cell type of Barrett’s esophagus secondary to GERD?
non-Keratinized stratified squamous to non-ciliated simple columnar with goblet cells
What are the two major causes of GERD?
- Hiatal hernia
- lower LES pressure
What are the two types of hiatal hernias?
- Sliding (cardia of the stomach protrudes into the esophagus)
- Paraesophageal (stomach herniates next to the esophagus in the diaphragm)
What is the appearance of a sliding hiatal hernia on Ba swallow?
Hourglass appearance
What is the classic physical exam sign of paraesophageal hiatal hernias?
Bowel sounds in the thorax
How does GERD cause asthma and cough?
Irritation of the airways from reflux
What are the dental findings of GERD?
Increased acid = damaged enamel
Where are the stem cells in the layers of the stomach? What is the significance of this in relation to GERD?
Mucosa–if knock out the mucosa, then will heal by fibrosis, causing a loss of the tone present in the LES
What is the most common type of esophageal cancer in the West? What is this usually associated with? Where in the esophagus does this usually occur?
- Adenocarcinoma
- Barrett’s esophagus
- Distal 1/3
What is the most common esophageal cancer worldwide? Where in the esophagus does this usually arise?
- SCC
- upper or middle third of the esophagus
What is the cause of SSC of the esophagus?
Irritation of the esophagus
How do Achalasia and esophageal webs lead to SCC?
Irritation via food degradation sitting in the esophagus
What are the s/sx of SCC of the esophagus? (3)
- Progressive dysphagia
- Hematemesis
- Hoarse voice/cough
—–Where does lymph flow in the upper 1/3 of the esophagus? Middle? Distal?—–
- —–Upper = cervical nodes
- Middle = mediastinal or tracheobronchial nodes
- Lower = celiac and gastric nodes——
Why is it that esophageal SCC can present with hoarse voice?
Invasion of the SCC beyond the BM may lead to compression of the recurrent laryngeal nerve
What is gastroschisis?
Congenital malformation of the abdominal wall, causing an exposure of abdominal contents
What is an omphalocele?
Persistent herniation of bowel into the umbilical cord, due to failure of herniated intestines to return to the body cavity during development
What comprises the cover of omphaloceles? How about in a gastroschisis?
- Peritoneum and amnion of the umbilical cord
- Nothing for a gastroschisis
What way does the intestines rotate during development, when it is in the umbilical yolk stalk?
Counterclockwise 270 degrees
What is the cause of pyloric stenosis? Which gender is this more common in?
- Hypertrophy of the pyloric smooth muscle
- Males
When does the pyloric stenosis usually form relative to birth? What are the s/sx?
- 2 weeks after birth
- Non-bilious projectile vomiting and olive-like mass in the abdomen
What is the treatment for pyloric stenosis?
Myotomy of the pyloric sphincter
What is acute gastritis? What are the two ways in which this occurs?
Increase acid production or decreased mucosal protection in the stomach, causing degradation of the stomach by acid
What are the two type of chronic gastritis?
- Chronic autoimmune gastritis
- Chronic H.Pylori gastritis
What are the three major components of mucosal protection from stomach acid? (3)
- Mucus (foveolar cells)
- Bicarb secretion
- Blood flow (picks up acid)
What are Curling ulcers?
Stomach ulcers in the context of a severe burn d/t hypovolemia and lower blood flow to the stomach.
What is a cushing ulcer?
Increased intracranial pressure, causing increased vagal stimulation, and increased ACh, which increases acid production
What are the effects of prostaglandins on the stomach? (3)
- Increase mucus and bicarb secretion from foveolar cells
- Decrease acid secretion
- Increase blood flow to the stomach to sweep away acid
What are the three receptors on parietal cells in the stomach that lead to increased acid secretion?
- Histamine (paracrine)
- ACh (neurotransmitter)
- Gastrin (Endocrine)
What is the cell in the stomach that creates acid? What other important protein does this secrete?
- Parietal cell
- Intrinsic factor
What is the MOA of shock causing ulcers?
Hypovolemia causes decreased blood flow to the stomach lining
What are the three outcomes of acid damage in the stomach, and how are each of these defined?
- Superficial inflammation
- Erosion (loss of epithelial layer)
- Ulceration (loss of mucosal layer)
What is the pathophysiology of chronic autoimmune gastritis? What type of hypersensitivity reaction is this? What is the significance of the antibodies produced in this?
Autoimmune destruction of parietal cells (and/or intrinsic factor). This is a type IV hypersensitivity rxn
-Antibodies are a consequence of the damage, not the cause of it
What are the two places in the stomach that parietal cells are common in?
- Fundus
- Body
What is the achlorhydria seen in chronic autoimmune gastritis?
Lack of acid production secondary to loss of parietal cells
What happens to acid levels, gastrin levels, and G cells in chronic autoimmune gastritis?
- Decrease acid
- Increased gastrin
- Antral G cell hyperplasia
Pernicious anemia has a high or low MCV?
High
What is the most common cause of vitamin B12 deficiency? What is this disease called?
- Autoimmune chronic gastritis
- Pernicious anemia
Why are pts with chronic, autoimmune gastritis at an increased risk for gastric adenocarcinoma?
Chronic irritation / inflammation induces metaplasia of the foveolar cells with goblet cell formation
What is the most common cause of chronic gastritis?
H.Pylori infx
What are the two enzymes that H. Pylori secretes that allow it to live on the stomach lining?
- Urease
- Proteases
What is the most common site of H.Pylori infection?
Antrum of the stomach
Does H.Pylori invade the stomach mucosa?
No
Why are pts with chronic gastritis at an increased risk for MALT lymphoma?
generation of germinal center and post germinal center B cells from the MARGINAL zone
What is the treatment for gastric carcinoma/MALT lymphoma secondary to H.Pylori infection?
Triple therapy (PPI, Az, Clindamycin)
What are the two ways in which you could confirm that the treatment for H.Pylori was effective?
- Negative urea breath test
- No H.Pylori antigen in the stool
What is the most common site of peptic ulcers?
Proximal duodenum
What is the major cause of PUD?
H.Pylori infection
What are the s/sx of duodenal PUD?
Epigastric pain that improves with meals
What is Zollinger-Ellison syndrome?
CA of the gastrin secreting portions of the stomach, causing increased acid release and ulcer formation
Why are the symptoms of PUD improved with meals?
Duodenum will increased HCO3 secretion, neutralizing the acid
What is the most common complications of PUD rupture?
Rupture of the walls of the duodenum
What happens if there is a rupture of the anterior wall of the duodenum?
Air beneath the diaphragm
What happens if there is a rupture of the posterior wall of the duodenum? (What organ and artery are at risk)?
- Acute pancreatitis
- Gastroduodenal artery rupture
Why is it that gastric ulcer symptoms worsen with meals?
increased acid secretion
What are the two most common causes of gastric ulcers?
- NSAID use
- H. Pylori
What artery is at risk if a gastric ulcer ruptures along the lesser curvature of the stomach?
Left gastric artery
True or false: duodenal ulcers are almost never malignant?
True
What are the gross characteristics of a non-cancerous ulcer in the stomach?
Flat. small, with well defined borders
What are the gross characteristics of a cancerous ulcer in the stomach?
Large, irregular and piled up borders
Gastric carcinoma is a malignant proliferation of what cells? What type of cancer, then, does this lead to?
Surface epithelial cells (adenocarcinoma)
What are the two general types of gastric carcinomas?
- Intestinal
- Diffuse
What are the features of the intestinal type of ulcer?
large, irregular ulcer with heaped up margins
Where are intestinal gastric carcinomas usually found in the stomach?
Along the lesser curvature of the antrum
What are the 3 risk factors for intestinal type gastric carcinoma? (food chemicals, blood type, etc)
- Nitrosamines
- Blood type A
- Intestinal metaplasia
What are the histological characteristics of diffuse type gastric carcinomas?
Signet rings cells that diffusely infiltrate the gastric wall
What causes the thickening of the stomach wall in diffuse type gastric carcinoma? What is this called?
- Desmoplasia
- Linitis plastica
True or false: The diffuse type of gastric carcinoma is not associated with H.Pylori infx, metaplasia, or nitrosamines
True
What are the s/sx of gastric carcinoma? (besides pain and weight loss) (4)
- Early satiety
- Anemia
- Abdominal pain
- Weight loss
What is the Leser-Trelat sign? What GI malignancy is this seen in?
The Leser-Trélat sign is the explosive onset of multiple seborrheic keratoses often with an inflammatory base.
This can be seen with Gastric carcinoma!
Distant mets from gastric carcinomas usually involve what organ?
- Liver
- Periumbilical region
- Bilateral ovaries
What is the sister Mary Joseph nodule?
mets from gastric CA to the periumbilical region
—-What is the Krukenberg tumor?—-
—-Bilateral mets from gastric CA to the ovaries—-
What is duodenal atresia?
failure of the small bowel to canalize
What genetic disease is duodenal atresia associated with?
Down syndrome
What are the s/sx of duodenal atresia? (3, in utero and postpartum)
- Polyhydramnios
- Double bubble sign
- Bilious vomiting
What is the vomiting like in pyloric stenosis? Duodenal atresia?
- Pyloric stenosis = non-bilious
- Duodenal atresia = bilious
What is Meckel diverticulum? Is this a true diverticulum?
true diverticulum that arises due to a failure of vitelline duct to involute
What is the vitelline duct?
Pathway that receives nutrients from the yolk sac during development
Passing of meconium via the umbilicus at birth = ?
Failure of the vitelline duct to involute
Soft stool in the periumbilical region of an infant’s abdomen = ?
Meckel diverticulum
What is the most common congenital anomaly of the GI tract? What percent of births does this occur in?
- meckel diverticulum
- 2%
What are the rule of twos for Meckel diverticulum? (4)
- 2% of the population
- 2 inches long
- Located within 2 feet of the ileocecal valve
- Presents within 2 years of life
What are the complications with meckel diverticulum? (3)
- Bleeding
- Volvulus
- Intussusception
True or false: The majority of cases of Meckel diverticulum are symptomatic
false– most are asymptomatic
What is a volvulus?
twisting of bowel along its mesentery, resulting in an obstruction and infarction
What is the most common location of a volvulus?
- Sigmoid colon (elderly)
- Cecum (young)
What are the stools that occur with intussusception?
“Currant Jelly” stools
What is a “leading edge” in intussusception?
An outpouching of the wall of the intestines that acts for the proximal part of the bowel to hang onto, and pull
What is the most common cause of a leading edge in infants? Adults?
- Infants = lymphoid hyperplasia
- Adults = Tumor
Why is the small bowel particularly susceptible to ischemic injury?
Uses a ton of ATP for transport of nutrients across the mucosa
What type of infarction can occur with embolism/thrombosis of the SMA or mesenteric veins?
Transmural
What is the mechanism by which infarctions of only the mucosa of the intestines occur?
Marked hypotension
What are the three clinical features of small bowel ischemia/infarction?
- Abdominal pain
- Bloody diarrhea
- Decreased bowel sounds
What is the pathophysiology celiac disease? What is the most pathogenic component of wheat?
- Immune mediated damage of the small bowel due to gluten exposure
- Gliadin
What are the gene loci that are associated with Celiac disease?
HLA DQ2 and DQ8
What are the three monosaccharides that are absorbed by the small intestines?
- Fructose
- Glucose
- Galactose
What is the enzyme that deamidates gliadin? What happens immunologically when this occurs?
- tTG (tissue transglutaminase)
- Deamidated gliadin is presented by APCs and MHC II
What immune cells are involved in Celiac disease and mediate the tissue damage?
Helper T cells
What is dermatitis herpetiformis seen in Celiac disease? Treatment / prognosis for this?
- IgA deposition at the tips of the dermal papillae, causing herpes-like blisters in the skin
- This resolves with a gluten-free diet
What are the three IgA antibodies that can occur with Celiac disease?
- Endomysium
- tTG
- Gliadin
What antibody subclass is used for celiac diagnosis if the pt does not produce IgA?
IgG
What are the three histological findings of Celiac disease?
- Flattening of the villi
- Hyperplasia of the crypts
- Increased intraepithelial lymphocytes
Which part of the small intestines is most affected by Celiac disease?
Duodenum
What two malignancies should you think of if a pt with Celiac disease presents with similar symptoms, despite good dietary control?
Small bowel carcinoma and T cell lymphoma
What is the pathophysiology of tropical sprue? When does it classically present?
Small bowel villi destruction by an unknown organism, after treatment for infectious diarrhea with Abx
What part(s) of the intestines are most affected by tropical sprue? What nutritional deficiencies can occur because of this?
- Jejunum and ileum
- Folate and B12 deficiency, since these are absorbed here
What is the difference of location of intestinal changes between Celiac disease and tropical sprue?
celiac = duodenum Tropical = jejunum and ileum
What is the causative agent of Whipple’s disease?
Tropheryma Whippelii
Where does Tropheryma Whippelii reside in the body (which cells/ which layer)?
Within macrophages along the lamina propria of the small bowel
What causes the fat malabsorption with Whipple’s disease?
Compression of lacteals by macrophages involved in inflammatory response
What are the s/sx of Whipple’s disease? Why?
Steatorrhea / fat malabsorption d/t accumulation of organisms within the lamina propria of the intestines
Where do chylomicrons that are synthesized in the intestinal enterocytes go when absorbed? How does this release to the steatorrhea in Whipple’s disease?
- Lamina propria to Lacteals to lymphatics.
- Deposition of diseases macrophages will clog this up
What is the histological appearance of the macrophages in the lamina propria in whipple’s disease? What is the stain that can be used to highlight these?
Foamy macrophages that are highlighted by PAS staining
What are the four places that Whipple’s disease affects besides the GI tract?
- Synovium of the joints
- Cardiac valves
- Lymph nodes
- CNS
What is abetalipoproteinemia, and how is it inherited? What does this cause?
AR deficiency of -apoB48 and apoB100
-fat malabsorption and absent LDL
What is the function of apoB48? B100?
- B48 = structural protein of the chylomicron
- B100 = structural protein of VLDL and LDL
What are carcinoid tumors?
malignant proliferations of neuroendocrine cells, causing a low grade malignancy
What is the worst type of neuroendocrine tumor?
Small lung cell carcinoma
What is the immunohistological stain that is used to identify carcinoid tumors?
Chromogranin
What is Chromogranin?
Stain used to identify Carcinoid tumors
What is the most common site for the development of carcinoid tumors in the GI tract? What does this appear as?
Small bowel–grows as a submucosal polyp-like nodule
What is the chemical that Carcinoid tumors secrete? What is the lab test for this?
- 5HT
- 5-HIAA (metabolite of 5HT) will be found in the urine
What happens when carcinoid tumors metastasize to the liver?
Are now able to dump 5HT directly into the portal vein, without being processed by the liver first
What is the cause of carcinoid heart disease?
Liver mets of carcinoid tumors dump 5HT directly into hepatic vein/IVC, causing fibrosis of the right heart, leading to tricuspid regurg and valvular stenosis
What are the three symptoms of 5HT overproduction by carcinoid tumors? What can trigger these?
- Bronchospasm
- Diarrhea
- Flushing
- EtOH or emotional distress
Why is it that carcinoid tumors that met to the liver cause only left sided valvular stenosis and tricuspid regurg, and NOT right sided problem?
Lungs have MAO, which will metabolize the excess 5HT
—What is the metabolite of 5HT that is made by MAO, and secreted in the urine?—-
—-5-HIAA—-
What are the two major causes of acute appendicitis? Which is more common to children? Adults?
Obstruction via lymphoid hyperplasia (children) or fecaliths (adults)
What are the s/sx of a ruptured appendix?
Peritonitis that presents with guarding and rebound tenderness
What are the three classical characteristics of IBD?
Young jewish female with recurrent bloody diarrhea and abdominal pain
What parts of the GI wall are involved in ulcerative colitis?
Mucosal and submucosal (not muscularis or serosa)
What parts of the GI wall are involved in Crohn’s disease?
Transmural (all parts of the wall)
Where does ulcerative colitis usually begin? What is the most proximal place it can involve?
- Rectum, works its way up
- Cecum is the most proximal it can go
Which is contiguous, and which has skip lesions: ulcerative colitis, Crohn’s disease
ulcerative colitis is contiguous
Crohn’s disease has skip lesions
Crypt abscesses are found in what disease (histologic hallmark)?
Ulcerative colitis (PMNs in crypts)
What is the gross appearance of ulcerative colitis?
Pseudopolyps and loss of haustra
What are the complications of ulcerative colitis?
toxic megacolon and carcinoma
What is the disease that is classically associated with ulcerative colitis?
Primary sclerosing cholangitis
What is the effect of smoking on ulcerative colitis? Crohn’s disease?
UC = protects against CD= increases risk
What are the two factors that are used to predict the risk of developing carcinoma from ulcerative colitis?
Extent of colonic involvement
Duration of the disease
What is the antibody that is found in ulcerative colitis?
pANCA
What parts of the GI tract can Crohn’s disease affect? What is the least common site?
- Mouth to anus
- Rectum is the least common site
What are the usual symptoms of CD?
RLQ pain with non-bloody diarrhea
What is the inflammation seen in UC? CD?
UC = crypt abscesses CD = Granulomas
What is the gross appearance of CD?
Cobblestone mucosa
What are the complications with CD?
Malabsorption
fistula formation
What causes the contractions, stenosis, and the “creeping fat” of the GI tract with CD?
Fibroblasts in the granulomas cause fibrosis and contraction
What is the “string sign” suggestive of?
CD
What extra-GI disease is CD associated with?
Ankylosing spondylitis
Why are kidney stones more common with CD?
Increased ability for CaCO3 to be absorbed into the blood
“lead pipe appearance” on x-ray is suggestive of which IBD? What causes this?
Ulcerative colitis d/t loss of haustra
Why is it that the emesis is non-bilious with pyloric stenosis?
Gastric contents have not yet entered the intestines
How can chemotherapy cause stomach ulcers?
Decrease cell turnover in the stomach lining
What are the two ways of acquiring lactose intolerance?
- Loss of enzymes physiologically
- Temporary loss of enzyme from a GI infection