bowel diseases: large intestine Flashcards
Diseases of the Colon and Rectum
Irritable bowel syndrome Antibiotic-associated colitis Inflammatory Bowel Disease: Crohn disease Ulcerative colitis (UC)
Diseases of the Colon and Rectum 2
Diverticular disease Diverticulosis Diverticulitis Polyps Familial adenomatous polyposis Hamartomatous polyposis syndromes Lynch syndrome
IBS
An idiopathic clinical entity characterized by chronic (more than 6 months) abdominal pain or discomfort that occurs in association with altered bowel habits
Symptoms may be continuous or intermittent
Definition of irritable bowel syndrome is abdominal discomfort or pain that has two of the following three features:
- Relieved with defecation
- Onset associated with a change in frequency of stool
- Onset associated with a change in form (appearance) of stool
IBS: Other symptoms supporting the diagnosis include ??
abnormal stool frequency; abnormal stool form (lumpy or hard; loose or watery); abnormal stool passage (straining, urgency, or feeling of incomplete evacuation); passage of mucus; and bloating or a feeling of abdominal distention
IBS epi
Patients may have other somatic or psychological complaints such as dyspepsia, heartburn, chest pain, headaches, fatigue, myalgias, urologic dysfunction, gynecologic symptoms, anxiety, or depression
Common problem presenting to both gastroenterologists and PCPs
-Up to 10% of the adult population have symptoms compatible with the diagnosis, but most never seek medical attention
-Approximately two-thirds of patients with irritable bowel syndrome are women.
IBS Pathophysiologic mechanisms have been identified:
Abnormal Motility
Visceral Hypersensitivity
Enteric Infection
*Psychosocial Abnormalities
IBS presentation
Chronic condition
*Diagnosis of exclusion
Symptoms usually begin in the late teens to twenties
Abdominal pain usually is intermittent, crampy, and in the lower abdominal region
Patients with irritable bowel syndrome may be classified into one of three categories based on the predominant bowel habit:
- Irritable bowel syndrome with diarrhea
- Irritable bowel syndrome with constipation
- *Irritable bowel syndrome with mixed constipation and diarrhea
“Alarm symptoms” that suggest a diagnosis other than irritable bowel syndrome and warrant further investigation
Acute onset of symptoms
Nocturnal diarrhea, severe constipation or diarrhea, hematochezia, weight loss, and fever
Family history of cancer, inflammatory bowel disease, or celiac disease
-dx of exclusion
IBS s/s
The physical examination usually is normal
Abdominal tenderness, especially in the lower abdomen, is common but not pronounced.
IBS labs
The use of routine blood tests (complete blood count, chemistry panel, serum albumin, thyroid function tests, erythrocyte sedimentation rate) is unnecessary in most patients
Stool specimen examinations for ova and parasites should be obtained only in patients with increased likelihood of infection
Routine sigmoidoscopy or colonoscopy is not recommended in young patients with symptoms of irritable bowel syndrome without alarm symptoms but should be considered in patients who do not improve with conservative management
IBS labs2
In all patients age 50 years or older who have not had a previous evaluation, colonoscopy should be obtained to exclude malignancy
When colonoscopy is performed, random mucosal biopsies should be obtained to look for evidence of microscopic colitis
-In patients with IBS with diarrhea, serologic tests for celiac disease should be performed
-Routine testing for bacterial overgrowth with hydrogen breath tests are not recommended
(labs not usually helpful)
IBS tx
-General measures: Reassurance, education, and support
-Dietary Therapy: intolerances
-Pharmacologic Measures: Antispasmodic agents, Antidiarrheal agents,
Anticonstipation agents
-Psychotropic agents: SSRIs
-Nonabsorbable antibiotics, Probiotics
-Psychological Therapies: Cognitive behavioral therapies, relaxation techniques, hypnotherapy
Antibiotic-Associated Colitis
(C. diff is a subset) Common clinical occurrence
Occurs during the period of antibiotic exposure, is dose related, and resolves spontaneously after discontinuation of the antibiotic
In most cases, this diarrhea is mild, self-limited, and does not require any specific laboratory evaluation or treatment
Antibiotic-Associated Colitis labs
Stool examination usually reveals no fecal leukocytes, and stool cultures reveal no pathogens
- Although C difficile is identified in the stool of 15–25% of cases of antibiotic-associated diarrhea, it is also identified in 5–10% of patients treated with antibiotics who do not have diarrhea
- Most cases of abx-associated diarrhea are due to changes in colonic bacterial fermentation of carbohydrates and are not due to C difficile
Antibiotic-Associated Colitis epi
- C difficile colitis is the major cause of diarrhea in patients hospitalized for more than 3 days, affecting 22 patients of every 1000
- Fastidious hand washing and use of disposable gloves are helpful in minimizing transmission
- C difficile is acquired in approximately 20% of hospitalized patients, most of whom have received antibiotics difficile colitis will develop in approximately one-third of infected patients
Antibiotic-Associated Colitis tx
Prophylactic administration of the probiotics who are receiving antibiotics reduced the incidence of C difficile–associated diarrhea
-Symptoms usually begin during or shortly after antibiotic therapy but may be delayed for up to 8 weeks
Antibiotic-Associated Colitis presentation
- Most patients report mild to moderate greenish, foul-smelling watery diarrhea 5–15 times per day with lower abdominal cramps
- Normal abdominal exam or mild left lower quadrant tenderness
- Colitis is most severe in the distal colon and rectum
- Over half of hospitalized patients diagnosed with C diff colitis have a white blood count greater than 15,000/mcL
- Severe or fulminant disease occurs in 10–15% of patients
Antibiotic-Associated Colitis: labs/imaging
Stool studies: Rapid enzyme immunoassays (EIAs)
Nucleic acid amplication tests (PCR assays)
Flexible sigmoidoscopy: Not needed with typical symptoms and positive stool toxin assay
Can see true pseudomembranous colitis in severe cases
Imaging studies:
For severe disease
Abnormal radiographs or noncontrast abdominal CT
Antibiotic-Associated Colitis tx
Antibiotic therapy should be discontinued
- Start metronidazole, PO vancomycin, or fidaxomicin (PO flagel for mild cases)
- For patients with severe disease, PO vancomycin and IV metronidazole
- Early sx consult is recommended for all patients with severe or fulminant disease
- Total abdominal colectomy or loop ileostomy with colonic lavage may be required in patients with toxic megacolon, perforation, sepsis, or hemorrhage
Antibiotic-Associated Colitis: Treatment of relapse
- Up to 25% of patients have a relapse of diarrhea from C diff within 1-2 weeks after stopping initial therapy
- Most relapses respond promptly to a second course of the same regimen used for the initial episode
- For patients with two relapses, a 7-week tapering regimen of vancomycin is recommended
- Probiotic therapy is recommended as adjunctive therapy in patients with relapsing disease
For patients with 3+ relapses of Antibiotic-Associated Colitis, updated 2013 guidelines recommend consideration of an ??
installation of a suspension of fecal bacteria from a healthy donor “fecal transplantation” into the terminal ileum or proximal colon (by colonoscopy) or into the duodenum and jejunum (by nasoenteric tube)
IBD: Know the differences between Crohn disease and Ulcerative Colitis (UC)
slide 19, first aid 362
For Crohn, think of a FAT GRANny and an old crone SKIPping down a COBBLESTONE road away from the wRECk (rectal sparing).
Ulcerative colitis causes ULCCCERS: Ulcers
Large intestine
Continuous, Colorectal carcinoma, Crypt abscesses
Extends proximally Red diarrhea Sclerosing cholangitis
Crohn Disease (worse of the 2)
One-third of cases of Crohn disease involve the small bowel only, most commonly the terminal ileum (terminal ileitis, B12 def)
-Half of all cases involve the small bowel and colon, most often the terminal ileum and adjacent proximal ascending colon (ileocolitis)
-In 20% of cases, the colon alone is affected
One-third of patients have associated perianal disease
-Less than 5% patients have symptomatic involvement of the upper intestinal tract
Unlike ulcerative colitis, Crohn disease is a ??
?? is strongly associated with the development of Crohn disease, resistance to medical therapy, and early disease relapse
transmural process that can result in mucosal inflammation and ulceration, stricturing, fistula development, and abscess formation
Cigarette smoking (in UC get better if smoke!)
Crohn disease May present with a variety of symptoms and signs
Physical examination should focus on the ??
History of fevers, general sense of well-being, weight loss, the presence of abdominal pain, the number of liquid bowel movements per day, and prior surgical resections
patient’s temperature, weight, and nutritional status, the presence of abdominal tenderness or an abdominal mass, rectal examination, and extraintestinal manifestations
Crohn’s: 5 common presentations (can overlap)
Chronic inflammatory disease Intestinal obstruction Penetrating disease and fistulae Perianal disease Extraintestinal disease (arthralgia, pyoderma gangrenosum, slide 27)
