Here are a few myths about diverticulosis and diverticulitis: - Eating seeds, nuts, or popcorn will not cause a diverticulum to perforate. While a high-fiber diet may help prevent diverticula, there is no evidence that certain foods directly cause a diverticulum to rupture. - Most people with diverticulosis will never develop diverticulitis. Only a minority (15-25%) of those with diverticulosis will have an episode of diverticulitis. - Mild or moderate diverticulitis can often be treated without antibiotics. For uncomplicated cases, a liquid diet and pain medications may be sufficient. Antibiotics are usually reserved for more severe

1. Author(s): Rebecca W. Van Dyke, M.D., 2012
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3. M2 GI Sequence
A GI Smorgasbord:
Common GI Problems – Part I
Rebecca W. Van Dyke, MD
Winter 2012

4. Industry Relationship
Disclosures
Industry Supported Research and
Outside Relationships
• None

5. Topics
• Hiatal hernia
• Gas
• Constipation
• Diverticuli/Diverticulitis
• Hemorrhoids

6. Hiatal Hernia
James Heilman, M.D., Wikimedia Commons
A large hiatus hernia on X-ray marked by open arrows in
contrast to the heart borders marked by closed arrows

7. Hiatal hernia: extremely common
Schematic diagram of different types of
hiatus hernia. Green is the esophagus, red is
the stomach, purple is the diaphragm, blue is
the HIS-angle. A is the normal anatomy, B is
a pre-stage, C is a sliding hiatal hernia, and D
is a paraesophageal type. Wikipedia

8. Views of a Hiatal Hernia
Esophagus
Gastric
mucosa in
hernia
Diaphragm
indentation
View from esophagus View from stomach
into hernia back up into hiatal
hernia

9. Radiologic evidence of
hiatal hernia

10. Consequences of Hiatal Hernia
• Benign
• Usually asymptomatic
• May predispose to
development of acid
reflux (and
complications)
• Rarely, gastric ulcers
develop within hiatal
hernia

11. Gas

12. Gas Facts
• Gas is a normal constituant of the GI tract
• Bowel sounds are due to turbulent flow/
mixing of liquid and gas in the tubular
intestines
• What goes in must come out
• Everyone passes flatus many times per
day but most people are not aware of
most of these passages
• Most people pass gas (infused into the GI
tract) very rapidly

13. Origin of Intestinal Gas
Input: H2S
NO2
Air swallowing trace gases
O2
Acid neutralization +
H2 CO2
Bacterial CO2 H+ +
HCO
fermentation, CH4 -
= CO
3
CO2
2
H2
metabolism
O2
CHO CH4
Output:
Eructation
Diffusion (lungs)
Flatus
N2, O2, H2, CO2, CH4, trace gases

14. Normally, gas does not accumulate in the
bowel as it is rapidly passed through the GI
tract.
30 ml/min
12 ml/min
4 ml/min

15. Thus, usually
there is only a
modest amount
of gas in the
GI tract (~200 ml)
at any one time.
This is a normal
gas pattern

16. Some patients
do have too
much gas, due
to: Colon
obstruction
dysmotility
(ileus)
This patient Small
has excess gas bowel
in both
colon and
small bowel, due
to profound ileus
and continued
input from
air swallowing.

17. Excess gas in colon - much less in small bowel

18. Gas Symptoms
• However, most people with “gas”
symptoms have normal amounts of gas in
the GI tract
• Instead they have sensations of increased
gut distension and/or increased flatus
• True increases in gas (and symptoms)
ususally arises from:
– Excess air swallowing
– Excess bacterial fermentation of carbohydrate

19. “GAS” symptoms: common
complaints of many patients
• Bloating
• Belching
• Enlarged abdomen
• Excess flatus

20. Many Causes of Bloating
Abnormal viscerosomatic Mucosal immune
Reflexes/abdomino-phrenic activation
dyscoordination
Food sensitivity/
Altered gut flora/ food intolerance
Abnormal colonic
fermentation
Gender/
sex hormones
Excessive gas/ Bloating
focal or general
GI gas accumulation/
Abdominal distention
CNS-ENS
abnormal gas handling dysregulation/
psychological factors
Visceral
hypersensitivity
Altered motility
Abnormal
visceral Constipation/
reflexes hard stools

21. The typical
normal gas
pattern seen
in most patients
with “excess
gas” complaints

22. Most Common Cause of
Bloating
• Sense of overdistension of stomach or
bowels
– Abnormal sensation with normal volume of
gas
– ?Due to poor “compliance” of stomach/gut
– Triggers eructation/belching
– Abdominal muscles relax leading to increased
abdominal girth

23. Bloating Perception and Response
of Abdominal Wall
Figure. Abdominal
imaging in a patient with
functional gut disorder.
Note anterior abdominal
wall protrusion and
diaphragmatic
descent during bloating
compared with basal with
only a small increase (by
22 mL) in gas content.
Accarino et al. Gastroenterology 136:1544, 2009

24. By contrast: a patient with bowel
obstruction or dysmotility

25. Patient-initiated Treatment:
Eructation/Belching
Patients feel “full” or “bloated”
Common response = belch
Eructation may release
some gastric gas

26. Belching/Eructation Facts
In the supine position, patients cannot belch
as liquid forms a water seal between gastric gas
and esophagus.

27. Belching Can Worsen Symptoms
3
1. Patients feel “full” or 2
“bloated”
2. However, prior to belch,
patient swallows
additional air
3. The LES relaxes, releasing
air
4. Net volume of air in GI
tract may increase.
5. Bloating sensation may
continue or even worsen.

28. Better Rx: Decrease Input
• Air swallowing accounts for virtually all air
in the upper GI tract
• Occurs during eating, drinking, talking and
dry swallows
• Can be reduced by
– Reduce belching/eructation
– Using straw
– Tilt glass/cup so fluid is above upper lip
– Not chewing gum, sucking on candies
• “Gas” from carbonated drinks plays a
minor role in most people

29. Other Gas Symptoms
• Enlarged abdomen: “my belly sticks out”
– Due to reflex relaxation of anterior abdominal
muscles
• Rx:
– reassure patient
– loosen clothes

30. Lower Gas Symptoms: Flatus
• Normal process – 5-20 times per day
• Increased by
– Changes in air/gas intake (air swallowing)
– Intake of foods containing undigestible
carbohydrates (remember lactose)
– Carbohydrate malabsorption (disease)
– Altered bacterial flora
• Some individuals do pass excess and/or especially
malodorous flatus, likely due to variations in colon
bacterial flora
• Noxious flatus involves sulfer-containing
compounds (onions, meat, cabbage etc.)

31. Foods Can Cause Flatus:
Plants make many interesting compounds
• Fruit juices, sodas
– fructose, sorbitol
• Cruciferous vegatables (cabbage family)
– sulfur-containing compounds (odoriferous gas)
• Beer (sulfer compounds)
• Legumes (dried beans)
– melitose, stachyose, raffinose
• Sugar-free gums/candies
– sorbitol, mannitol
• Milk
– lactose

32. Treatment of “Gas”: Poor Evidence
• Reassurance
• Reduce air swallowing and suppress belching
• Promotility agents (metoclopramide)
• Agents that alter gas bubble surface tension
(simethicone)
• Identify and eliminate intake of poorly absorbed
carbohydrates/other foods associated with
gas
• Alter bacterial flora (lactobacillus or yeast
“probiotics”)
• Bismuth subsalicylate (Pepto-Bismol) or zinc for
H2S
• Consider evaluation for malabsorptive disorders

33. Constipation
• Definition
– <3 stools per week
– Hard stool, difficult to pass
– Straining, sensation of incomplete evacuation
• Prevalence (self-perceived): 10-20%
• Occasional constipation is a part of normal
life for most humans

34. Constipation: Pathophysiology - I
• Liquid material enters cecum from ileum
• Colon’s job:
– Reabsorb electrolytes (Na, Cl, K) and water
– Salvage nutrients, utilizing bacterial
fermentation
– Move material, in a timely manner, to rectum
for appropriate defecation
• Constipation or diarrhea usually reflect
imbalances in these functions

35. Constipation: Pathophysiology - II
• Slow colon transit
– Motility decrease (diabetes, hypothyroidism)
– Drugs (narcotics, Ca channel blockers,
anticholinergics, Ca/Al antacids, cholestyramine)
– Idiopathic
• Increased bowel Na/H2O absorption (?)
• Insufficient fiber - ?”natural laxative”
– Unabsorbed complex carbohydrate
– Increases stool bulk
– Fermented to osmotically active compounds
• adds water to stool
– May stimulate colon motility

36. Constipation: Pathophysiology - III
• Insufficient bile acids or endogenous pro-
secretory or osmotically active compounds
• Defecatory problems
– Anal sphincter
– Pelvic floor dysfunctions
• Psychological factors/eating disorders

37. Enterohepatic Circulation of Bile Acids:
recycling is efficient
Bile acid
synthesis
Bile acids cycle between
the liver and the small
intestine.
Liver Total bile acid pool is
about 3 grams.
About 90% of bile acids
are reabsorbed in the
terminal ileum.
However about 5-10% of
bile acids are lost daily
into the colon. Effect?
Liver synthesizes about
Small bowel 5-10% of the total bile acid
Colon pool each day.

38. Enterohepatic Circulation of Bile Acid
Cholestyramine:
Bile acid bile acid binding resin
synthesis that removes bile acids
from the enterohepatic
circulation
Liver Liver upregulates bile acid
synthesis (using up
what compound in the
process?)
If liver cannot keep up,
what happens?
Less free bile acid in
the colon causes what?
Small bowel
Colon

39. Constipation: Rx
• Alter underlying factors if possible
• Add fiber – start slow (1-2 T/day) and increase weekly
– High fiber foods
– Purified fiber (metamucil, citracel, psyllium)
– Side effect: flatus
• Add osmotic agent – start slow (1-2 T/day), increase
weekly
– MOM, sorbitol, lactulose (lactose), polyethylene glycol (Miralax)
• Consider promotility agent
– (metoclopramide)
• Consider stimulant laxatives (motor/?secretory effects)
– Anthranoids (senna, Senokot, aloe, cascara etc.)
– Polyphenolic compounds (bisacodyl/Dulcolax, phenophthalein, sodium
picosulfate)
• Monitor response to therapy with stool diary

40. Constipation: Myth Busting
• Having 1 stool a day is not required for
health
– Normal range is 1 every 3 days up to 3/day
– Thus, reassurance often works
• More exercise rarely works (controlled trial was
done)
• Drinking more water/fluids rarely works
– Water is absorbed and excreted by kidneys
• Colace (dioctyl sodium sulfosuccinate), a
detergent, has no effect on stool weight or
frequency in controlled studies.

41. Diverticuli of the Colon: A phenomenon
of aging and ? too little dietary fiber?

42. Opening of diverticulum as seen from
the lumen of the colon.

43. Saccular Colonic Diverticuli
Very large diverticuli in a woman with scleroderma. She had undergone a barium
swallow study one day before, leading to oral contrast accumulating in the
colonic diverticuli.

44. Diverticuli

45. Complications of Diverticuli
• Stool/particulate matter accumulates in the
diverticulum
• Mucosa inside diverticulum ulcerates and
erodes into the underlying artery
– Diverticular bleed
• Obstruction of diverticulum leads to
infection, perforation and contained
abscess outside the wall of the colon
– Diverticulitis

46. Diverticulitis: if a perforation
occurs, the contents can travel.
The usual
route is
into
omentum

47. Diverticular perforation - outcomes
Abscesses can
Local, confined erode into nearby
perforation and structures
local infection
(diverticulitis)
Free rupture of
diverticulum
Rupture of
with release of
diverticular
free air and infection
abscess
into peritoneum

48. Diverticulitis
A 70-year-old, previously healthy man had had sudden, colicky lower abdominal pain and
increased urinary frequency for four days
Nanda, R. et al. N Engl J Med 1995;333:498

49. Diverticulitis
Thickening of colon wall in region of inflammation
Compression of colon lumen by inflammation

50. Diverticuli can bleed

51. Diverticular bleeds are arterial – thus bleeding is often
massive. Since most diverticuli are in the distal colon,
the blood passed is often bright red.

52. Myth Busting: Diverticulitis
• Clinical teaching states that patients with diverticuli should avoid nuts,
seeds, popcorn intake to reduce the chance that these might obstruct the
mouth of diverticuli and cause diverticulits.
• There is no evidence for this but it has become imbedded in medical/nursing
lore.
• This article (JAMA 300:907-914, 2008) is an 18 year study of 47,000 men
and there actually was an inverse relationship between intake of these food
items and development of diverticulitis or other complications.
• Please do not tell your patients to avoid these foods for this reason.

53. Hemorrhoids: they have been
around a long time.
Illuminated manuscript from 1190-1198

54. Anal Anatomy
No
pain
Pain
Vascular cushions (“plexus”) provide for fine control of
continence, but can be injured, enlarge, stretch and “sag”.

55. Pathophysiology: Hemorrhoidal
Disease
• Vascular basis
– cushions of soft tissue with large vascular channels
• Injury/age/passage of hard stool damages or
fragments these cushions or their supporting
structures
• Straining increases venous pressure and
engorgement of these tissues
• Once tissues prolapse, damage progressively
worsens
• Trauma causes epithelial damage leading to
ulceration, bleeding, pain
• Thrombosis of external hemorrhoids causes pain

56. Appearance
WikipedianProlific, Wikimedia Commons
Internal: above the dentate line – not painful unless prolapsed
External: below the dentate line – may be painful

57. Visual inspection makes the
diagnosis
Large external hemorrhoids
or
severely prolapsed internal hemorrhoids

58. Prolapsed Internal Hemorrhoid

59. Internal hemorrhoids - view from
the endoscope
Bleeding

60. Complications of Hemorrhoids
• Pain/irritation/discomfort
– prolapsed internal hemorrhoids
– ulcerated or thrombosed external hemorrhoids
• Bleeding
– small amounts of bright red blood
– rarely a major bleed
• Leakage of liquid/stool
– Prolapsing internal hemorrhoids impair tight closure of
the anal sphincters

61. Medical Management:
Little Evidence-Based Therapy
• To prevent or reduce hemorrhoids:
– Soften stool, reduce straining
– fiber, osmotic agents
• To treat pain/irritation:
– Topical creams (OTC)
– Anusol suppositories with hydrocortisone
– 5-ASA suppositories
– Sitz baths (soak in warm water)
– Donut ring to sit on

62. Treatment of Hemorrhoids
1 – Sclerosis-internal
2 – Banding - internal
3 – Infrared photocoagulation - internal
4 – Surgery – internal and external

63. Rubber band ligation

64. Part II will be on Thursday,
February 9 at 11:10 a.m.

65. Additional Source Information
for more information see: http://open.umich.edu/wiki/CitationPolicy
Slide 6: James Heilman, M.D., Wikimedia Commons, http://upload.wikimedia.org/wikipedia/commons/3/3a/HiatusHernia10.JPG, CC:BY-SA,
http://creativecommons.org/licenses/by-sa/3.0/deed.en
Slide 56: WikipedianProlific, Wikimedia Commons, http://upload.wikimedia.org/wikipedia/commons/7/7b/Hemorrhoid.png, CC:BY-SA,
http://creativecommons.org/licenses/by-sa/3.0/deed.en