3. Large Intestine
Large Intestine.
The large intestine, also known as the large bowel, is the last part of the
gastrointestinal tract and of the digestive system
Water and other nutrients is absorbed here and the remaining waste
material is stored as feces before being removed by defecation.
large intestine is about five feet (or 1.5 meters) long
It's about 3 inches (around 7.6 centimeters) wide.
4.
5. Sections of Colon
the colon consists of six sections:
the cecum,
the ascending colon,
the transverse colon,
the descending colon,
the sigmoid colon,
the rectum.
7. Types and Causes:
1. Ulcerative colitis.
UC is a lifelong disease that causes inflammation and bleeding ulcers within
the inner lining of your large intestine. It generally begins in the rectum and
spreads to the colon.
UC is the most commonly diagnosed type of colitis. It occurs when the
immune system overreacts to bacteria and other substances in the
digestive tract (Crohn’s Disease)
8. Common types of UC include:
proctosigmoiditis, which affects the rectum and lower portion of the colon
left-sided ulcerative colitis, which affects the left side of the colon
beginning at the rectum
pancolitis, which affects the entire large intestine
9. 2. Pseudomembranous colitis
Pseudomembranous colitis (PC) occurs from overgrowth of the bacterium
Clostridium difficile (C. diff). This kind of bacteria normally lives in the
intestine, but it doesn’t cause problems because it’s balanced by the
presence of “good” bacteria.
Certain medications, especially antibiotics, may destroy healthy bacteria.
This allows C. diff to take over, releasing toxins that cause inflammation.
10. Ischemic colitis
Ischemic colitis (IC) occurs when blood flow to the colon is suddenly cut off
or restricted. Blood clots can be a reason for sudden blockage.
Atherosclerosis, or buildup of fatty deposits in the blood vessels that supply
the colon, is usually the reason for returning IC.
(the superior mesenteric artery (SMA) and inferior mesenteric artery
(IMA)
11. This type of colitis is often the result of underlying conditions. These may include:
vasculitis, an inflammatory disease of the blood vessels
diabetes
colon cancer
dehydration
blood loss
heart failure
obstruction or blockage
trauma or injury
12. Microscopic colitis –
a colitis diagnosed by microscopic examination of colonic tissue;
macroscopically ("to the eye") it appears normal.
Lymphocytic colitis
Collagenous colitis
13. Lymphocytic colitis.
Lymphocytic colitis is a subtype of microscopic colitis, a condition
characterized by chronic non-bloody watery diarrhea.
The colonoscopy is normal but histology of the mucosal biopsy reveals an
accumulation of lymphocytes in the colonic epithelium and connective tissue
(lamina propria)
14. Collagenous colitis
occurs when the colon’s lining becomes thicker than usual due to a buildup of
collagen under the outermost layer of tissue
Microscopic colitis causes chronic watery diarrhea with greater than 10
bowel movements per day. Some patients report nocturnal diarrhea,
abdominal pain, urgency, fecal incontinence, fatigue, dehydration and weight
loss.
15. Sings and Symptoms:
abdominal pain or cramping
bloating in your abdomen
unexpected weight loss
diarrhea with or without blood
Mucus and/or blood in stool and rectal bleeding
chills or fever
Vomiting
Erythema (redness) of the surface of the colon
Fatigue
Joint pain or soreness
Eye pain when you look at a bright light
16. Complications:
Severe bleeding
A hole in the colon (perforated colon)
Severe dehydration
Bone loss (osteoporosis)
Inflammation of your skin, joints and eyes
An increased risk of colon cancer
A rapidly swelling colon (toxic megacolon)
Increased risk of blood clots in veins and arteries
17. Diagnosed:
CBC
colonoscopy, which involves threading a camera on a flexible tube through
the anus to view the rectum and colon
sigmoidoscopy, which is similar to a colonoscopy but shows only the rectum
and lower colon
stool samples
abdominal imaging such as MRI or CT scans
ultrasound, which can be useful depending on the area being scanned
barium enema, an X-ray of the colon after it’s injected with barium, which
helps make images more visible
18. Treatment:
Anti-inflammatory drugs
Anti-inflammatory drugs are often the first step in the treatment of
ulcerative colitis and are appropriate for the majority of people with this
condition. These drugs include:
5-aminosalicylates. Examples of this type of medication include sulfasalazine
(Azulfidine), mesalamine (Asacol HD, Delzicol, others), balsalazide (Colazal)
and olsalazine (Dipentum). Which one you take, and whether it is taken by
mouth or as an enema or suppository, depends on the area of your colon that's
affected.
Corticosteroids. These drugs, which include prednisone and budesonide, are
generally reserved for moderate to severe ulcerative colitis that doesn't
respond to other treatments. Due to the side effects, they are not usually
given long term
19. Immune system suppressors
These drugs also reduce inflammation, but they do so by suppressing the
immune system response that starts the process of inflammation
Immunosuppressant drugs include:
Azathioprine (Azasan, Imuran) and mercaptopurine (Purinethol, Purixan).
These are the most widely used immunosuppressants for the treatment of
inflammatory bowel disease. Taking them requires that you follow up closely
with your doctor and have your blood checked regularly to look for side
effects, including effects on the liver and pancreas.
20. Cyclosporine (Gengraf, Neoral, Sandimmune). This drug is normally reserved
for people who haven't responded well to other medications. Cyclosporine has
the potential for serious side effects and is not for long-term use.
Tofacitinib (Xeljanz). This is called a "small molecule" and works by stopping
the process of inflammation. Tofacitinib is effective when other therapies
don't work. Main side effects include the increased risk of blood clots.
21. Biologics
These are made from proteins in living cells instead of chemicals. Types of
biologics used to treat ulcerative colitis include:
Infliximab (Remicade), adalimumab (Humira) and golimumab (Simponi).
These drugs, called tumor necrosis factor (TNF) inhibitors, or biologics,
work by neutralizing a protein produced by your immune system. They are for
people with severe ulcerative colitis who don't respond to or can't tolerate
other treatments.
22. Vedolizumab (Entyvio). This medication is approved for treatment of
ulcerative colitis for people who don't respond to or can't tolerate other
treatments. It works by blocking inflammatory cells from getting to the site
of inflammation.
Ustekinumab (Stelara). This medication is approved for treatment of
ulcerative colitis for people who don't respond to or can't tolerate other
treatments. It works by blocking a different protein that causes
inflammation.
23. Antibiotics
Anti-diarrheal medications
Pain relievers. For mild pain, acetaminophen (Tylenol,
Antispasmodics
Iron supplements.
24. Surgery.
If other treatments don’t work or your UC is severe, you might need surgery
to remove your colon (colectomy) or colon and rectum (proctocolectomy). If
you have a proctocolectomy, your doctor might make a small pouch out of
your small intestine and attach it to your anus. This is called ileal pouch-anal
anastomosis (IPAA). It lets your body expel waste normally, so you don’t need
to wear a bag to collect stool.