CM- Approach to Colon and IBD Flashcards
How does the colonic mucosa differ from intestinal mucosa?
Colonic - intestinal epithelium. with specialized cells to absorb and secrete, lamina propria and muscularis mucosa
Colon does NOT have villi and consists mainly of crypts.
What is the definition of constipation?
- decrease in # of BMs
2. difficulty defacating regardless of # of stools
What are the 2 causes of constipation and how do you differentiate them?
- Colonic inertia (pumps too slow)
- outlet obstruction
To differentiate, a radioopaque markers (Sitz) is ingested.
If the markers are scattered throughout the colon is is colonic inertia.
If the markers are concentrated at the distal colon it is an outlet obstruction.
What is treatment for constipation?
- increase stool water content (bulking agent or non-reabsorbable liquid like miralax)
- Biofeedback if patient has pelvic floor dysenergia
What is pseudo-obstruction and what are the causes?
It is when there is colonic dilation and signs/symptoms of obstruction with no obstructing lesion present.
- smooth muscle disorder
- myenteric plexus
- neuro dysfunction
- endocrine/metabolic disorders
5 drugs - idiopathic ** most common
What is treatment for pseudo-obstruction?
- rule out colonic obstruction by hypaque enema
2. position changes to move air toward the rectum
What is fecal incontinence?
What are 3 decently common causes?
What is treatment/management?
It is when stool cannot be retained until voluntary evacuation.
It is common with previous trauma to the anal canal so:
1. pregnancy
2. prior hemorrhoid surgery
3. diabetes
Treatment:
- exercise pelvic floor muscles
- biofeedback
- US to see if the sphincter is amenable to surgery
What are the 4 most important structural diseases of the colon?
- obstruction
- CRC
- diverticular disease
- IBD
A patient presents with abdominal distension and obstipation [they have not been able to pass any luminal contents including gas]. They now feel nauseas and have vomited multiple times.
What is the likely problem?
What 4 things are the most common causes?
Obstruction-
- intraperitoneal adhesions
- torsion of the colon upon itself (volvulus)
- intraluminal mass (cancer)
- diverticular stricture
What is microscopic colitis?
What is seen grossly?
What do labs show?
What is noted histologically?
Chronic watery diarrhea with no blood, abdominal pain, or signs of malabsorption.
Lab tests and gross examination are normal, however, histology shows chronic inflammatory cells.
- lymphocytic colitis
- collagenous colitis
What are the 2 types of idiopathic IBD?
- UC
2. Crohn disease
What part of the GI tract is affected by UC?
What are typical GI symptoms?
What are systemic symptoms?
UC affects the entire colon but not other parts of the gut.
Typical symptoms are small volume bloody diarrhea.
Systemically they can experience fever and malaise.
What are the most dreaded complications of UC?
- Toxic megacolon - risk for perforation)
- Primary sclerosing cholangitis (PSC)
- Cholangiocarcinoma
- colon cancer
What part of the GI tract is affected by Crohn disease?
What are systemic symptoms?
CD is a disease of the entire intestinal wall and has skip areas of the colon starting on the right side. It can affect any area of the GI tract from nasopharynx to rectum.
Systemic manifestations of Crohn are:
- symmetric arthralgias in appendicular joints
- gallstone disease
- renal stones
How are treatments different for Crohn and UC?
They are essentially the same, except for surgical considerations.
- surgery is curative in UC, not Crohn
- UC can’t get segmental resections. Take the whole colon
- Crohn must get segmental resections and thus multiple surgeries over lifetime
- Ileal pouch reconstructions with anal anastamoses lead to long term continence in total proctocolectomies in UC patients