HLTH 2501: lower GI tract disorders Flashcards
gliadin
a breakdown product of gluten
celiac disease
is a malabsorption syndrome that occurs due to a defect in the intestinal enzymes that prevents the digestion of glidin, causing a toxic effect in the intestinal villi
effect of celiac disease on the villi
the villi atrophy, resulting in decreased enzyme product and less surface area available for nutrient absorption
effect of celiac disease
mainly is malabsorption and malnutrition which manifest as steatorrhea, muscle wasting, failure to gain weight, and irritability and malaise; individuals are at a higher risk for intestinal lymphoma
steatorrhea
excessive amounts of fat in your poop
how is celiac dianogsed?
blood tests that check for autoantibodies, a duodenal biopsy, and testing a gluten-free diet
how is celiac disease treated?
gluten-free diet
what are chronic inflammatory bowel diseases (2)
crohn disease and ulcerative colitis
genetic causes of IBD
common in white persons, particularly those from Eastern Europe
serum levels of those with IBD
high levels of antibodies, human leukocyte antigen, cytoskins, interleukin, and T lymphocytes
differences between Crohn’s and ulcerative colitis
Crohn’s develops during adolescence and ulcerative colitis in later years
what areas of the GI tract does Crohn’s effect?
the terminal ileum and sometimes the ascending colon
inflammation in Crohn’s disease
occurs in skip lesions, which are affected segments clearly separated by areas of normal tissue; initially occurs in the mucosal layer, but will progress to affect all layers of the wall
intestines of those with Crohn’s disease
narrow lumen that may become totally obstructed, granulomas may appear, and motility is decreased, thus decreasing the time for digestion and absorption
effects of Crohn’s disease
hypoproteinemia, avitaminosis, malnutrition, and possibly steatorrhea; ulcers may also form
signs of Crohn’s disease
diarrhea with cramping, melena may occur if the uclers erode blood vessels, pain in the LRQ, anorexia, weight loss, anemia, fatigue, delayed growth, and psychological implications
where does ulcerative colitis occur
in the rectum and throughout the colon
inflammation in ulcerative colitis
inflammation occurs in the mucosa and the submucosa, and the tissue becomes edematous (swollen) and friable (easily crumbled), and ulcers develops; in an attempt to heal, granulation tissue develops
toxic megacolon
occurs in severe acute episodes of ulcerative colitis; inflammation impairs peristalsis, leading to obstruction and dilation of the colon, usually the transverse colon
risks of ulcerative colitis
colorectal carcinoma
signs of ulcerative colitis
diarrhea with blood and mucus, cramping pain, tenesmus (persistent spasms of the rectum), rectal bleeding, iron-deficiency anemia, fever, and weight loss
treatment of IBD
removing physical and emotional stressors, anti inflammatory medications, antimotility agents, nutritional supplements, antimicrobials, immunotherapeutic agents, and surgical procedures such as an ileostomy and colostomy
anti inflammatory drugs for IBDs
sulfasalazine or glucocorticoids
antimotility drugs for IBDs
loperamide or anticholinergic drugs
recommended diet for IBDs
high in protein, vitamins, and calories, but low in fat
antimicrobials for IBDs
metronidazole or ciprofloxacin
IBS
a gastrointestinal disorder characterized by abdominal pain/discomfort and changes in normal bowel habits
primary symptoms of IBS
symptoms of diarrhea, constipation, or pain
different types of IBS
abnormal GI motility and secretion, visceral hypersensitivity, post infectious IBS, overgrowth of flora, food allergy or intolerance, and psychosocial factors
abnormal GI motility and secretion IBS
diarrhea or constipation that is caused by hypersensitivity or serotonin on the ENS
visceral hypersensitivity IBS
increased sensitivity to visceral pain; can be abnormal motility but also activated mast cells and T lymphocytes or the CNS
postinfectious IBS
caused by low-grade inflammation in the gut and an abnormal immune response; often is associated with bacterial enteritis
overgrowth of flora IBS
can cause constipation and bloating due to methane gas production which is a result of overgrowth of the normal flora in the gut
food allergy or intolerance IBS
certain food antigens activate the immune response in the mucosa, causing a hypersensitivity reactions and IBS symptons
psychosocial factors for IBS
IBS symptoms may be caused by emotional stress, which in turn affects the ANS and the neuroendocrine pathway
signs of IBS
lower abdominal pain, diarrhea, constipation, alternating diarrhea and constipation, gas, bloating, and nausea
diagnosis of IBS
based on the signs and symptoms and the exclusion of any metabolic problems; tests for food intolerances can confirm the diagnosis
rome criteria
an established guide for diagnosing IBS
treatment for IBS
may include laxatives, fiber supplements, antidiarrheal medication, antidepressants, analgesics for pain, antispasmodic medications, and medication to balance serotonin levels
two medications suggested for IBS treatment
alosetron (lotronex), this relaxes the colon and slows the movement of waste through the lower bowel; and lubiprostone (amitiza) which works by increasing fluid secretion in the intestine to help with the passage of stool
appendicitis
is an inflammation and infection in the vermiform appendix
how does appendicitis develop?
obstruction of the appendiceal lumen, fluid and microorganism buildup in the appendix, inflamed appendiceal wall, purulent exudate forms, ischemia and necrosis of the wall which results in increased permeability, bacteria and toxins escape the wall and which leads to abscess formation or localized bacterial peritonitis, local infection around the appendix which causes pressure, appendix will rupture or has to be removed
what obstructs the appendiceal lumen in appendicitis?
a fecalith (mass of feces), gallstone, or foreign material
abscess
a pocket of pus
why would the appendix bursting be dangerous?
because it would release its contents into the peritoneal cavity
signs of appendicitis
steady and severe pain and tenderness in the LRQ, nausea and vomiting, low-grade fever, and sometimes tachycardia or hypotension
treatment for appendicitis
surgical removal and antimicrobial drugs
diverticular disease
refers to problems related to the development of the diverticula
what is a diverticulum?
a herniation or outpouching of the mucosa through the muscle layer of the colon wall (commonly in the sigmoid colon)
diverticulosis
asymptomatic diverticular disease whereas multiple diverticula are present
diverticulitis
inflammation of the diverticula; common in the Western world
where do diverticulum develop?
in gaps between bands of longitudinal muscle that coincide with opening in the circular muscle bands, often in the sigmoid colon
what causes diverticula?
low-residue diets, irregular bowel habits, and aging lead to constipation and then to muscle hypertrophy, leading to the development of diverticula
problems that may arise with diverticula
intestinal obstruction, perforation with peritonitis, and abscess formation
signs of diverticular disease
usually is asymptomatic but signs may be mild discomfort, diarrhea, constipation, flatulence, LLQ pain, nausea, and vomiting
treatment for diverticula
increasing the bulk in the diet and omitting foods such as seeds and popcorn
colorectal cancer prevalence
common cancer and is the second leading cause of cancer-related deaths
polyp
is a mass, often on a stem that protrudes into the lumen; as they grow, they carry an increased risk of dysplasia and malignant changes
what do most malignant neoplasms result from in colorectal cancer?
adenomatous polyps
napkin-ring growth
carcinomas that commonly develop in the left colon
projecting polypoid masses
carcinomas that often develop in the right colon
what other areas of the body do colorectal neoplasms affect?
the mesentery, the abdominal wall, the lymph nodes, and the liver
what is staging of colorectal cancer based on?
the degree of local invasion, lymph node involvement, and the presence of disant metastases
what antigen do adenocarcinomas release into the blood?
CEA
risk population for colorectal cancer
those 55+, Western countries, familial multiple polyposis, long-term ulcerative colitis, genetic factors, and diets high in fat, sugar, and red meat, and low in fibre
signs of colorectal cancer in the rectosigmoid area
is often asymptomatic but can be obstruction in the proximal colon, vague cramping pain, ribbon stool, and feelings of incomplete emptyings
signs of colorectal cancer in the right colon
liquid fecal material, fatigue, weight loss, and iron-deficiency anemia
treatment for colorectal cancer
surgical removal of the involved area, usually requiring a colostomy; chemotherapy and radiation therapy may be used after surgery
colostomy
an artificial opening into the abdominal wall where feces may be collected in a bag
intestinal obstruction
refers to a lack of movement of the intestine contents through the intestine; more common in the small intestine than the large
two forms of intestinal obstruction
mechanical or functional
mechanical obstructions
result from tumors, adhesions, hernias, scar tissue, volvulus, or other tangible obstructions
functional obstructions
result from neurological impairment such as a spinal cord injury or a lack of propulsion
paralytic ileus
refers to functional intestinal obstructions resulting from neurological impairment
sequence of events for mechanical intestinal obstruction
gases and fluids accumulate, strong contractions occur to move contents, increased pressure leads to more secretions into the intestines, persistent vomiting, ischemic and necrotic intestinal wall, decreased peristalsis, rapid reproduction of bacteria, and generalised peritonitis
sequence of events for functional obstruction
peristalsis cease, fluids and electrolytes accumulate in the intestine, and reflex spasms do not occur; the result of the process is similar to mechanical obstruction
causes of functional intestinal obstructions
spinal cord injuries, after abdominal surgeries due to anesthesia combined with inflammation and ischemia, pancreatitis, peritonitis, ro infection in the abdominal cavity, and hypokalemia
volvulus
twisting of a section of intestine on itself
hirschsprung disease
a condition which parasympathetic innervation is missing from a section of the colon; can cause mechanical intestinal obstruction
how would Crohn’s or diverticulitis lead to mechanical intestinal obstruction?
chronic inflammation of the GI tract
signs of intestinal obstruction
abdominal pain, constipation, borborygmi, vomiting, restlessness, diaphoresis, tachycardia, dehydration and weakness due to electrolyte imbalances
borborygmi
audible rumbling sounds caused by movement of gas in the intestine
treatment for intestinal obstruction
treating the underlying causes and replacing fluids and electrolytes
peritonitis
an inflammation of the peritoneal membrane that may result from chemical irritation or from bacterial invasion; chemical irritation will lead to bacterial peritonitis
why might the peritoneal membrane be inflamed?
chemical irritants, chyme, or foreign objects in the cavity; this inflammation then increases permeability, allowing enteric bacteria to enter the cavity; necrosis of perforation also allows for bacterial entry
what initially occurs when local inflammation develops in the abdominal cavity?
the peritoneum and omentum produce a thick, sticky exudate to seal the area and localize the problem
peritoneum anatomy
a large sterile expanse of highly vascular tissue that covers the viscera and lines the abdominal cavity
results of peritonitis
increased permeability of vessels leads to large volumes of fluid in the cavity, followed by hypovolemic shock; fluid, proteins, and electrolytes are not circulating
causes of peritonitis
chemical peritonitis, bacterial peritonitis. abdominal surgery, and pelvic inflammatory disease
signs of peritonitis
generalized abdominal pain, vomiting, hypovolemia, dehydration, decreased skin turgor, dry buccal mucosa, pallor, low BP, tachycardia, fever, and decreased bowel sounds
treatment for peritonitis
surgery is often required to correct the cause and drain infection sites, antimicrobials, fluid and electrolyte replacement, and sometimes nasogastric suction
fistulas
form in those with Crohn’s when ulcers may erode through the abdominal wall; occur often between loops of intestine
immunotherapeutic agent for IBD
azathioprine
what in general does celiac disease cause?
a digestive block and an immune response
