Ch. 22 Chronic Constipation Presenting with Severe Abdominal Pain

Question 1

What clues on H&P help distinguish between a SBO and LBO?

Answer 1

SBOs tend to be associated with more pronounced vomiting.

In an early SBO, bowel sounds are hyperactive, with “rushes and tinkles” (high-pitched sounds of hyperperistaltic small bowel).

LBO more likely associated with more pronounced distension, less or late onset vomiting, and decreased bowel sounds.

Question 2

What is the classic px for Ogilvie’s Syndrome?

Answer 2

Ogilvie’s Syndrome = massive nonobstructive colonic dilatation

• Progressive massive abdominal distension over several days
• Nausea
• Vomiting (similar to LBO)

However, unlike LBO, classic setting is in someone who is already hospitalized and often in post-op setting.

Question 3

What are the 5 F’s of Abdominal Distension?

Answer 3

• Fat (obesity)
• Feces (fecal impaction)
• Fetus (pregnancy)
• Flatus (ileus or obstruction)
• Fluid (ascites)

Question 4

1. What are the most common causes of LBO?
2. Where in the colon is cancer most likely to cause an LBO?
3. What is the difference between malrotation and volvulus?

Answer 4

1. USA: malignancies (primarily colon cancer) > diverticulitis (either acute or chronic with stricture) > volvulus
2. Left-sided colon (smaller diameter) cancers / R-sided colon cancers more likely to present with IDA
3. Malrotation: congenital condition in which bowel does not reside in normal anatomic position –> bowel and its mesentery not properly fixed/attached and therefore prone to twisting and becoming obstructed
   Volvulus: twisting of the bowel; can be a manifestation of malrotation… if small bowel twists = midgut volvulus… volvulus can also occur in absence of malrotation

Question 5

Diverticulosis

1. What is diverticulosis?
2. What is the most common site?
3. Who is at risk?
4. What are the symptoms/complications?
5. What is the treatment?

Answer 5

1. False diverticula (only mucosa and submucosa herniate through bowel musculature)
2. 95% of people with diverticulosis have sigmoid colon involvement
3. At risk: people with low-fiber diets, chronic constipation, positive family hx
4. Bleeding
5. High-fiber diet

Question 6

Diverticulitis

1. What are the associated barium enema findings?
2. Is colonoscopy safe in an acute setting?
3. What is the most common fistula with diverticulitis?
4. What is the best test?
5. What is the initial therapy?
6. What type of surgery is usually performed for an acute case of diverticulitis with a complication (e.g., perforation, obstruction)?
7. How common is massive lower GI bleeding with diverticulitis?

Answer 6

1. Barium enema should be avoided in acute cases
2. No, there is an increased risk of perforation
3. Colovesical fistula (to bladder)
4. CT scan
5. Initial therapy: IVF, NPO, broad-spectrum abx with anaerobic coverage, NG suction (as needed for emesis/ileus)
6. Hartmann’s procedure: resection of involved segment with an end colostomy and stapled rectal stump (will need subsequent reanastomosis of colon usually after 2-3 post-op months)
7. Very rare! Massive lower GI bleeding is seen with diverticulosis, not diverticulitis.

Question 7

Colonic Volvulus

1. What is it?
2. What is the most common type of colonic volvulus?

Answer 7

1. Twisting of colon on itself about its mesentery, resulting in obstruction and, if complete, vascular compromise with potential necrosis, perforation, or both
2. Sigmoid volvulus (“floppy” structure)

Question 8

Sigmoid Volvulus

1. What is it?
2. What is the incidence?
3. What findings are evident on abdominal plain film?
4. What are the signs of necrotic bowel in colonic volvulus?
5. How is the dx made?
6. Under what conditions is gastrografin enema useful?
7. What are the signs of strangulation?
8. What is the initial tx?
9. What is the % of recurrence after nonoperative reduction of a sigmoid volvulus?
10. What are the indications for surgery?

Answer 8

Sigmoid Volvulus

1. What is it? Volvulus or “twist” in the sigmoid colon
2. What is the incidence? 75% of colonic volvulus cases (sigmoid = superior)
3. What findings are evident on abdominal plain film? Distended loop of sigmoid colon, often in classic “bent inner tube”, “coffee bean” or “omega” sign with loop aiming toward RUQ
4. What are the signs of necrotic bowel in colonic volvulus? Free air, pneumatosis (air in bowel wall)
5. How is the dx made? Sigmoidoscopy or radiographic exam with gastrografin enema
6. Under what conditions is gastrografin enema useful? If sigmoidoscopy and plain films fail to confirm the dx; “bird’s beak” is pathognomonic seen on enema contrast study as contrast comes to sharp end
7. What are the signs of strangulation? Discolored or hemorrhagic mucosa on sigmoidoscopy, blood fluid in rectum, peritoneal signs, fever, hypotension, increased WBC
8. What is the initial tx? NONOPERATIVE… if there is no strangulation, sigmoidoscopic reduction is successful in 85% of cases (ENDOSCOPY)
9. What is the % of recurrence after nonoperative reduction of a sigmoid volvulus? 40%
10. What are the indications for surgery? Emergently if strangulation suspected or nonoperative reduction unsuccessful (Hartmann’s procedure)

Question 9

Cecal Volvulus

1. What is it?
2. What is a cecal “bascule” volvulus?
3. What is the incidence?
4. What is the etiology?
5. How is the diagnosis made?
6. What diagnostic studies should be performed?
7. What is the treatment?
8. What are the major differences in the EMERGENT mgmt of cecal volvulus vs. sigmoid?

Answer 9

Cecal Volvulus

1. What is it? Twisting of the cecum opon itself and the mesentery
2. What is a cecal “bascule” volvulus? Instead of the more common axial twist, the cecum folds upward (lies on the ascending colon)
3. What is the incidence? 25% of colonic volvulus
4. What is the etiology? Idiopathic, CONGENITAL PARTIAL MALROTATION: poor fixation of the R colon, many pts have hx of abdominal surgery (vs. sigmoid = acquired condition)
5. How is the diagnosis made? Abdominal plain film; dilated ovoid colon with large air/fluid level in the RLQ often forming the classic “kidney bean/comma” sign with the apex aiming toward the epigastrium or LUQ (must r/o gastric dilation with NG aspiration)
6. What diagnostic studies should be performed? Water-soluble contrast study (gastrografin), if dx cannot be made by AXR
7. What is the treatment? Emergent surgery, R colectomy with primary anastomosis or ileostomy and mucous fistula
8. What are the major differences in the EMERGENT mgmt of cecal volvulus vs. sigmoid? Pts with cecal volvulus require surgical reduction, whereas vast majority of pts with sigmoid volvulus undergo initial endoscopic reduction of twist

Question 10

What are the risk factors for sigmoid volvulus?

Answer 10

Factors that lead to stretching and redundancy of the sigmoid:

• Anticholinergic drugs (which impair motility)
• Neurologic and psychiatric diseases (likely due to chronic constipation with stool retention)
• CF
• Chagas’ disease
• High fiber diet (creates large, bulky stools, that stretch out sigmoid colon)

** Occur more commonly in regions that are part of the so-called volvulus belt which includes Brazil, sub-Saharan Africa, and Middle East, where diets are high in vegetables and fruits **

Question 11

Work-Up

1. What are the first steps in the work-up of a suspected LBO?
2. What is the first imaging recommended for a suspected LBO?

Answer 11

Work-Up

1. CBC, serum lactate, and serum chemistries to determine electrolyte abnormalities and presence of dehydration
   
   1. Leukocytosis (with a left shift) and lactic acidosis = concerning for presence of bowel obstruction with ischemia, or complicated volvulus
2. _​_Plain abdominal (supine and upright) and upright chest radiographs (to look for free air under the diaphragm)

Question 12

Most common causes of LBO

Answer 12

Cancer

Diverticulitis

Volvulus