Skip to content

Short Bowel Syndrome [DT]

Summary of Nutrient Absorption in the Gastrointestinal Tract

  1. Jejunum:
    • Primary absorption site for:
      • Fat
      • Protein
      • Carbohydrates
    • Minerals absorbed:
      • Calcium (Ca)
      • Magnesium (Mg)
      • Iron (Fe)
      • Zinc (Zn)
      • Copper (Cu)
    • Vitamins absorbed:
      • Fat-soluble vitamins: A, D, E, K
      • Water-soluble vitamins: B, C, folate
  2. Ileum:
    • Primary absorption site for:
      • Bile acids
      • Vitamin B12
  3. Colon:
    • Responsible for the absorption of:
      • Water
      • Electrolytes

image.png

Short Bowel Syndrome (SBS)

  • Definition: SBS occurs when less than 200 cm of small bowel remains.

Minimum Length of Small Bowel for TPN Independence

  • 100 cm without colon.
  • 60 cm with colon.

Causes of Functional Short Bowel Syndrome

  • Radiation enteritis.
  • Low-grade or indolent malignancies (e.g., pseudomyxoma peritonei).
  • Refractory sprue.
  • Congenital villous atrophy.
  • Chronic intestinal pseudo-obstruction syndrome.

Prognosis Factors

  • Remaining length of functional intestine.
  • Presence of active diseases (Crohn's, radiation enteritis, vasculopathy).
  • Functional continuity of the colon and the ileocecal valve (ICV).

Table 79.2: Anatomic Subtypes of Short Bowel Syndrome

Subtype Resection/Remnant Avoidance of Permanent PN Dependence GI Tract Pathophysiology Clinical Manifestations
1. Jejunal-ileal anastomosis Majority of jejunum resected, 10+ cm of ileum, ICV, colon remain Usually good, but poor if <40 cm of jejunum remains Impaired digestion, increased gastric acid secretion Diarrhea
2. Jejunal-colic anastomosis All/most ileum resected. Parts of jejunum, colon may also be resected Variable but poor if <65 cm of jejunum remains Deficiencies in vitamin B12, bile salts, fat-soluble vitamins. Fat malabsorption Diarrhea, steatorrhea
3. End jejunostomy Some jejunum retained. Ileum, ICV, colon removed. End jejunal ostomy Variable but poor if <100 cm of jejunum remains Deficiencies in vitamin B12, bile salts, magnesium. Fluid and nutrient malabsorption Excessive ostomy output, dehydration

Keller’s 3 Phases of Intestinal Adaptation

  1. Acute Phase:
    • Post-resection to 4 weeks.
    • Goal: Stabilization.
  2. Adaptive Phase:
    • 1 to 2 years.
    • Goal: Achieve maximal intestinal adaptation.
  3. Maintenance Phase:
    • Long-term phase.
    • Goal: Optimize fluid balance.

Goals of Medical Management

  • Ensure nutritional absorption.
  • Maintain fluid and electrolyte balance.
  • Retain vitamins and trace elements.
  • Maintain nutritional status and weight.

Table 79.3: Drug Therapy Recommendations in the Acute Phase of Short Bowel Syndrome Management

Drug Dose per Day
Cholestyramine 4–16 g
Famotidine 40–80 mg
Loperamide 4–16 mg
Metronidazole 800–1200 mg
Pancreatic enzyme 25,000–40,000 U per meal
Octreotide 50–100 µg, 2–3 times per day
Omeprazole 20–40 mg
Ranitidine 300–600 mg

Small Bowel Bacterial Overgrowth (SBBO)

  • Common complication following Short Bowel Syndrome (SBS).
  • Pathophysiologic changes leading to bacterial overgrowth include:
    • Villous atrophy
    • Loss of gut-associated lymphoid tissue
    • Reflux of colon bacteria in the absence of the ileocecal valve (ICV)
    • Rapid intestinal transit time
  • Bacterial overgrowth threshold: Greater than 10^5 colony-forming units (CFU)/mL in the intestine.
  • Diagnosis:
    • Intestinal fluid culture.
    • Hydrogen breath testing.
  • Treatment:
    • Empiric treatment with broad-spectrum antibiotics and metronidazole.
    • Decrease carbohydrate load.
    • Antimotility agents are not used.
  • Most common organism: Coagulase-negative staphylococcal species.
  • Incidence ranges from 3% to 60% over the lifespan of the central venous catheter (CVC).
  • Associated with a 50% 5-year mortality rate.

1. Autogenous Intestinal Reconstruction Surgery (AIRS)

  • Primary objective:
    • Improve intestinal function.
    • Optimize bowel motility.
    • Increase the mucosal absorptive surface area.

2. Intestinal Transplant

Surgical Procedures

A. Procedures to Improve Intestinal Function

  • Stricturoplasty, lysis of adhesions, and segmental resection.
  • Reversal of stoma.

B. Procedures to Improve Motility

  • Reversal of intestinal segment.
  • Colonic interposition.
  • Intestinal tapering & plication.

C. Procedures to Increase Absorption

  • Longitudinal intestinal lengthening and tailoring (LILT).
  • Serial transverse enteroplasty (STEP).

image.png

LILT (Longitudinal Intestinal Lengthening and Tailoring)

  • Developed:
    • 1980: By Bianchi on pigs.
    • 1981: First human case by Beckman et al. (Gastroschisis).
  • Premise: LILT is based on the idea that a bifurcated blood supply exists within the mesentery.
  • Anatomic criteria for patient selection:
    1. Intestinal diameter greater than 3 cm.
    2. Residual small bowel length greater than 40 cm.
    3. Length of dilated bowel greater than 20 cm.

  • Disadvantages:

    • Technically challenging.
    • Cannot be repeated on the same intestinal segment.

    image.png

STEP (Serial Transverse Enteroplasty)

  • Developed:
    • 2003: By Kim et al. on 6 pigs.
  • Procedure:
    • Lengthens and tapers the small intestine.
    • The intestine is cut and reshaped into a longer, thinner segment, allowing for better absorption.
  • Principle: The small bowel blood supply from the mesentery runs perpendicular to the long axis of the small bowel.
  • Advantages:
    • Simpler and easily reproducible.
    • No bowel anastomosis required.

  • Disadvantage:

    • Postoperative asymmetrical redilation of the bowel.

    image.png

IOWA Procedure

  • Developed: By Kimura et al., reported in 1993.
  • Indication:
    • Used when the mesentery is shortened or only the duodenum is remaining.
  • Procedure:
    • First stage: Deseromyotomizing the antimesenteric surface of the dilated bowel segment to a host organ such as:
      • Deperitonealized abdominal wall (Iowa Model I).
      • Decapsulated liver (Iowa Model II).
      • Adjacent bowel with incised serosa (Iowa Model III).
    • Second stage:
      • Longitudinal split of the parasitized antimesenteric bowel (developed blood supply) and the mesenteric bowel (native blood supply).
  • Disadvantage:
    • Requires multiple laparotomies.

Indications for Small Bowel Transplant

  • IFALD (Intestinal Failure-Associated Liver Disease)
  • Parenteral Nutrition (PN) Failure
  • Single episode of fungemia
  • More than 2 Central Venous Catheter-Related Infections (CRI) per year
  • Shock or ARDS (Acute Respiratory Distress Syndrome) due to CRI
  • Thrombosis of 2 out of 6 major central veins
  • Alterations in growth in children
  • Severe dehydration
  • Impending liver failure
  • Established cirrhosis or portal hypertension

These are the critical factors that may necessitate a small bowel transplant in patients with intestinal failure or complications from prolonged parenteral nutrition.

MCQs for Revision

1. Short bowel syndrome occurs when remaining small bowel is less than:

A) 100 cm

B) 200 cm

C) 300 cm

D) 400 cm

Correct Answer: B) 200 cm

2. All of the following are causes for functional SBS except:

A) Radiation enteritis

B) Refractory sprue

C) Congenital villous atrophy

D) Crohn's disease

Correct Answer: D) Crohn's disease

(Crohn's disease typically causes mechanical SBS rather than functional SBS.)

3. Vitamin B12 & bile salts are mainly absorbed in:

A) Duodenum

B) Proximal jejunum

C) Proximal ileum

D) Distal ileum

Correct Answer: D) Distal ileum

4. The primary energy source for growth and metabolism of enterocytes is:

A) Glucose

B) Fatty acid

C) Glutamine

D) Amino acid

Correct Answer: C) Glutamine

5. Lactose is mainly absorbed in:

A) Duodenum

B) Proximal jejunum

C) Proximal ileum

D) Distal ileum

Correct Answer: B) Proximal jejunum

6. Diarrhea & steatorrhea are classically present in which anatomic subtype of SBS:

A) Jejunoileal anastomosis

B) Jejunocolic anastomosis

C) End jejunostomy

D) End colostomy

Correct Answer: B) Jejunocolic anastomosis

7. Which of the following procedures done in SBS is to increase the absorptive area:

A) Colonic interposition

B) Intestinal tapering & plication

C) Serial transverse enteroplasty (STEP)

D) Stricturoplasty

Correct Answer: C) Serial transverse enteroplasty (STEP)

8. Teduglutide is used in the management of:

A) Morbid obesity

B) Radiation proctitis

C) Short bowel syndrome

D) Irritable bowel syndrome

Correct Answer: C) Short bowel syndrome

9. Which of the following drugs is not used in the management of short bowel syndrome:

A) Omeprazole

B) Loperamide

C) Metronidazole

D) Metoclopramide

Correct Answer: D) Metoclopramide

(Metoclopramide is not typically used in the management of SBS.)

10. Which of the following is not an indication for small bowel transplantation:

A) Thrombosis of at least two central veins

B) Absence of portal hypertension

C) Fungemia

D) Intestinal failure associated liver disease

Correct Answer: B) Absence of portal hypertension

11. Acute cellular rejection is most common with: ? ? ?

A) Small bowel transplant alone

B) Combined small bowel-liver transplant

C) Multivisceral transplant

D) Equal in all three

Correct Answer: A) Small bowel transplant alone ? ? ?

These MCQs cover key concepts related to Short Bowel Syndrome, small bowel transplant, and other related procedures and medications.