Editing Pouchitis


Inflammation of the pouch after an IPAA (ileal pouch-anal anastomosis)

== Epidemiology ==

* Incidence 55% after IPAA

== Risk factors ==

* Previous UC
** More extensive disease
** Extraintestinal      manifestations including PSC
** Younger age at diagnosis or      surgery
* Coexisting autoimmune or     autoinflammatory disorders
* Obesity
* Smoking (acute pouchitis)
* Possibly dietary factors
* Possibly J pouches at higher     risk than S pouches (?less tension)
* PV thrombosis
* Faecal stasis

== Aetiology ==

* Uncertain
** May be related intestinal      microbiota
*** Quantity of bacteria?
*** Decreased microbial       diversity?
*** Biosynthetic capability?
*** Specific pathogens?
**** C diff common
** Genetic factors implicated
** Abnormal mucosal immunity
** Ischaemia
** Anastomotic complications

== Pathophysiology ==

* Maybe an abnormal immune     response to altered luminal and/or mucosal bacteria in genetically     susceptible hosts

== Classification ==

* Acute vs chronic (<4     weeks)
* Frequency of flares
** Episodic (<3 episodes per      year)
** Relapsing (>=3/year)
** Chronic
* Disease extent
* Antibiotic-responsive or     resistant
** May evolve over time to be      resistant
* Pouchitis Disease Activity     Index (PDAI)

{| class="wikitable"
|'''Clinical criteria'''
|
|-
|Stool frequency
|
|-
|Usual post-op  stool frequency
|0
|-
|One to two  stools/day > post-op usual
|1
|-
|Three or more  stools/day > post-op usual
|2
|-
|Rectal bleeding
|
|-
|None or rare
|0
|-
|Present daily
|1
|-
|Fecal  urgency/abdominal cramps
|
|-
|None
|0
|-
|Occasional
|1
|-
|Usual
|2
|-
|Fever (temperature  >100°F)
|
|-
|Absent
|0
|-
|Present
|1
|-
|'''Endoscopic criteria'''
|
|-
|Edema
|1
|-
|Granularity
|1
|-
|Friability
|1
|-
|Loss of vascular  pattern
|1
|-
|Mucus exudate
|1
|-
|Ulceration
|1
|-
|'''Acute histologic criteria'''
|
|-
|Polymorph  infiltration
|
|-
|Mild
|1
|-
|Moderate + crypt  abscess
|2
|-
|Severe + crypt  abscess
|3
|-
|Ulceration per  low-power field (average)
|
|-
|<25 percent
|1
|-
|≥25 to ≤50 percent
|2
|-
|>50 percent
|3
|}

* Pouchitis     is defined as a total PDAI score ≥7 points.
* There     is a modified version that does not require histology

== Presentation ==

* Broad spectrum of severity     and natural history
* Increase in stool frequency
* Urgency
* Bleeding is rare - more     suggestive cuffitis, pouch prolapse, or ulcers
* Systemic infective symptoms     are uncommon, and suggest an infective cause of pouchitis, Crohn disease     of the pouch, or surgical complications
* Straining or ineffective     defecation is more suggestive of an obstructive disorder such as stricture     or functional problem with pelvic floor
* Abdominal cramping, pelvic     pressure
* Tenderness of lower abdomen     may be present
* Elevated CRP
* Radiographic findings:
** Pouch thickening
** Mucosal hyperenhancement
** Accumulation of peri-pouch      fat
** Pelvic lymphadenopathy

== Differential diagnosis ==

* Ischaemic pouchitis -     asymmetric inflammation and ulceration of the pouch
* Cuffitis - recurrence of UC     in the residual cuff of rectal mucosa
** Haematochaezia,      circumferential inflammation of rectal cuff, typical UC histologic      findings
* CD of pouch
* Structural or functional     pouch outlet obstruction
* Post-op complications
* Pre-pouch ileitis
* Diversion pouchitis - anal     discharge of blood/mucus/urgency
* Irritable pouch syndrome
* De novo coeliac disease

== Workup ==

* Bloods
* Pouchoscopy and mucosal     biopsies
** Look for diffuse erythema,      friability, granularity, exudates, erosions, ulcerations
** Pre-pouch ileitis may be      present
** Don't biopsy the suture line      - may be reported as granulomas, wrongly suggestive of CD
* Stool studies to exclude     infection

== Management ==

* Treatment goals
** Alleviate symptoms
** Improve quality of life
** Achieve clinical and      endoscopic remission by demonstrating mucosal healing
* Primary prevention
** Minimise NSAIDs
** Maintain healthy weight
* Acute idiopathic pouchitis
** Avoid NSAIDs
** Diet low in poorly digested      carbohydrates and fibre (although there are variable recommendations…      refer to dietician with expertise)
** Oral antibiotic for two      weeks (ciprofloxacin 500mg BD, or metronidazole 500mg BD). If no      response, culture the stool and give four weeks of antibiotics based on      susceptibility.
** Pouch lavage?
* Relapsed acute pouchitis
** PO Abx
** Consider maintenance therapy      for those with frequent relapses
* Chronic pouchitis
** Probiotic
* CARP
** Screen for PSC, IgG4      disease, or other secondary cause
** Trial topical mesalamine for      four weeks
** If effective, basically      manage as UC
** Biologics are available for      refractory cases

== Prognosis ==

* Most patients with acute     pouchitis settle with antibiotics, but 50-90% will have at least one     recurrence and 30% will get chronic pouchitis
* If chronic     antibiotic-refractory pouchitis (CARP) develops, it may progress to pouch     failure requiring permanent diversion

[[Category:Colorectal]]