Bowel dysfunction following recto-sigmoid surgery: phenotypic variation within
anterior resection syndrome
Introduction:
Anterior resection of the rectum remains the mainstay of surgical management for most rectal and sigmoid
cancers. Intuitively, partial or complete loss of the rectal reservoir is likely to impact significantly on storage
and/or evacuation of faeces. The resulting symptom-complex of frequency, urgency, incontinence and/or
disordered defaecation has been loosely termed ‘anterior resection syndrome’. However, characterisation of this
syndrome remains suboptimal. Therefore, this study aimed to investigate symptoms of bowel dysfunction
following anterior resection surgery, and identify factors associated with symptom development.
Methods:
A prospective observational cohort study of consecutive patients who underwent anterior resection surgery for
colorectal cancer between 2002 and 2011 was performed using a self-administered questionnaire. Outcome
measures included subjective and objective assessment of bowel function. Subjective assessment of bowel
function included: (i) satisfaction with bowel function as assessed by the patient using a 7-point Likert scale; (ii)
need to seek medical attention for post-operative bowel dysfunction; (iii) self-described post-operative bowel
function; and (iv) self-reported change in bowel function following surgery. Objective assessment used
standardised criteria and scoring systems (Rome III criteria, Wexner and Vaizey scoring systems) to: (A)
document the presence of individual symptoms of bowel dysfunction; and (B) when present, group symptoms
together to allow stratification of patients into those with: (i) evacuation dysfunction, defined as having 2 or
more symptoms of obstructed defaecation; (ii) storage dysfunction, defined as faecal incontinence and/or having
2 or more symptoms of bowel frequency, loose stools, urgency, incontinence to flatus or need to wear a pad/plug
for faecal soiling; (iii) both evacuation and storage dysfunction, or (iv) neither – criteria not met. These outcome
measures were modelled against important clinicopathological features, including age, use of radiotherapy, and
technical details, including anastomotic height measured from the anal verge, and time since surgery.
Results:
Of the 754 patients who underwent surgery, 476 were alive and without stoma at the time of the study. Of these,
338 (71%) agreed to participate (199M, 69 years). Subjectively, over one quarter (26.4%) of patients were
dissatisfied with their current bowel function, and over one third (36.4%) had sought medical attention
specifically for post-operative bowel dysfunction. Only one third (36.4%) judged their current bowel function as
‘normal’, and two-thirds (62.2%) felt their bowel function had changed since surgery, with most reporting
increased frequency and looser stools. Objectively, at least one symptom of bowel dysfunction was present in
93% of patients. Notably, of the top 10 individual symptoms reported, 6 were reflective of evacuation
dysfunction, with two thirds of patients each reporting sensation of incomplete emptying (67.2%) and need for
toilet revisiting (63.4%). Following stratification, 85% of all patients met criteria for either evacuation or storage
dysfunction. Over half of all patients (51%) described coexisting evacuation and storage dysfunction; 23% met
criteria for evacuation dysfunction alone; and 11% met criteria for storage dysfunction alone. Patients with a
combination of evacuation and storage dysfunction had significantly lower satisfaction scores (P<0.001) and
higher rates of seeking medical attention. Anastomotic height was ≤5 cm in 26%, 6-10 cm in 23%, and 11-15cm
in 51% of subjects. Lower anastomoses were associated with storage dysfunction (P<0.001) but not evacuation
dysfunction. Neither gender nor radiotherapy with associated with storage or evacuation dysfunction.
Conclusions:
Individual symptoms of bowel dysfunction are ubiquitous following anterior resection surgery, with evacuation
dysfunction being more prevalent than storage dysfunction. The combination of evacuation and storage
dysfunction appears to have the greatest impact on satisfaction with bowel function and health-care seeking
behaviour, and symptoms may persist up to ten years post surgery. The phenotypic variation of bowel
dysfunction following anterior resection surgery demonstrates the need for a validated assessment tool to assess
outcomes in patients. Low anastomotic height is associated with storage but not evacuation dysfunction.
Institutions and Contact Details
1
Academic Colorectal Unit, Concord Hospital Campus, School of Medicine, University of Sydney, NSW,
Australia. Email: m.a.gladman@sydney.edu.au
2
Clinical and Population Perinatal Health Research, Kolling Institute of Medical Research, University of Sydney,
NSW, Australia
3
Department of Colorectal Surgery, The Whittington Hospital, London, United Kingdom