Small bowel obstruction

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

complete or complicated small bowel obstruction: surgery indicated

1st line – supportive care

Back

1st line –

supportive care

Treat patients in the accident and emergency department with fluid resuscitation bowel decompression, and analgesia.[4]

Small bowel obstruction is a surgical emergency, with a high risk of morbidity and mortality if not managed correctly.
Appropriate intervention is crucial. If untreated, patients may develop progressive intestinal ischaemia, necrosis, and perforation.
Follow local protocols if there are signs of sepsis. See our topic Sepsis for more information.

Consult a general surgeon early.[4][14] Operative treatment is indicated in patients with complete small bowel obstruction, peritonitis, or evidence of strangulation, and in those who do not respond to non-operative treatment.

If you suspect ischaemia or strangulation, arrange for surgery as soon as possible, and definitely within 6 hours of the suspected onset of ischaemia or strangulation.[4]

Assess the patient’s risk using appropriate risk prediction tools and your clinical judgement.[41]

Patients should have their risk of morbidity and mortality assessed and recorded in the medical records by a senior surgeon (CT3/ST3 or higher in the UK) within 4 hours of admission or transfer.[41]

Refer to a consultant and discuss ‘high-risk’ patients with a consultant within 1 hour.[16] Discuss the patient with the anaesthetic and critical care teams, if necessary.

A consultant review should take place in all patients diagnosed with acute bowel obstruction as soon as clinically indicated and at the latest within 14 hours of admission to hospital.
‘High risk’ is defined as where the risk of mortality is greater than 10%, or where a patient is unstable and not responding to treatment.[16]

Fluid resuscitation

Use intravenous fluids for patients with signs of shock or severe dehydration, or in patients unable to tolerate oral fluids.

Use an ABCDE approach to manage any patients with shock empirically. Ensure a patent airway and give oxygen if needed.

Treat the underlying cause as early as possible.
Escalate all patients with shock to a senior clinician.

See our topic Shock for full management recommendations.

Indicators that the patient may need urgent fluid resuscitation include:[13]

Systolic blood pressure less than 100 mmHg
Heart rate more than 90 beats per minute
Cold peripheries
Capillary refill time more than 2 seconds
Respiratory rate more than 20 breaths per minute
National Early Warning Score (NEWS2) of 5 or more ( NEWS2 Opens in new window)
Passive leg raising suggests fluid responsiveness.

Check local protocols for specific recommendations on fluid choice.

In these patients, administer fluid resuscitation and place a catheter to monitor urine output.[4][14]

Consider the requirements for insulin-dependent diabetes patients. Indications for a variable rate intravenous insulin infusion include patients with diabetes or hospital-related hyperglycaemia who can’t take oral food or fluid and where it’s not possible to adjust their usual insulin regimen.[42] For example, when:
- Vomiting
- Nil by mouth and the patient will miss more than one meal
- There is severe illness with a need to achieve good glycaemic control (such as with sepsis).
Get specialist advice from the diabetes team in these circumstances.

Fluid loss from vomiting, bowel wall oedema, and loss of absorptive capacity leads to dehydration and electrolyte imbalance (metabolic alkalosis).[40]

Use an intravenous fluid management plan with details of the fluid and electrolyte prescription over the next 24 hours, plus plans for assessment and monitoring.

This should be reviewed by an expert daily.[13]
- In this context, the UK-based National Institute for Health and Care Excellence defines an expert as a healthcare professional who has core competencies to diagnose and manage acute illness.[13]
Regularly monitor patients receiving intravenous fluids.[13]
- Clinical monitoring should include current status of:
  - NEWS2 ( NEWS2 Opens in new window)
  - Fluid balance charts
  - Weight.
- Laboratory investigations should include:
  - Full blood count
  - Urea
  - Creatinine
  - Electrolytes.

Seek expert help if patients have a complex fluid and/or electrolyte redistribution issue or imbalance, or significant comorbidity, such as:[13]

Gross oedema
Sepsis
Hyponatraemia or hypernatraemia
Renal, liver, and/or cardiac impairment
Postoperative fluid retention and redistribution
Malnourishment and refeeding issues.

Analgesia

Pain is one of the predominant symptoms. Assess pain at presentation and throughout the admission.[16]

Provide analgesia in line with your local protocol.[4][16][43] If needed, administer opioid analgesia such as intravenous morphine.[43] Check your local protocols for specific advice on choice of drugs and doses. Refer to the acute pain team if the patient’s pain is difficult to manage, but ensure that this does not delay definitive treatment.[16]

Screening and monitoring

Correct electrolyte disturbances.[14] Electrolyte imbalances are associated with both small bowel obstruction and paralytic ileus.[15]

Monitor the patient using an early warning score, such as the NEWS2 score. NEWS2 Opens in new window It measures the following parameters:[46]

Respiration rate
Oxygen saturation
Systolic blood pressure
Pulse rate
Level of consciousness or new-onset confusion
Temperature.

Undertake a nutritional screen, such as the Malnutrition Universal Screening Tool (MUST) score, and act on the results.[16] MUST calculator Opens in new window Provide nutritional support, if indicated.[14] Arrange review by a dietitian or the nutrition team.[16]

Consider nutritional support if a patient has not eaten for 5 days and may not be able to resume their usual diet within the next 5 days.[47]

Attend to other medical conditions, if present, such as diabetes. Consider anticoagulation reversal if surgery is likely.[4]

Assess frailty using a score, such as the Rockwood frailty score.[16][24] Rockwood Clinical Frailty Scale Opens in new window

Discuss patients with a high frailty score with the multidisciplinary team.
Establish a treatment escalation plan and record resuscitation status.
Arrange a risk assessment, with input from critical care.[16]

Primary options

morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response

Plus – nasogastric decompression

Back

Plus –

nasogastric decompression

Treatment recommended for ALL patients in selected patient group

Prevent aspiration of vomit by gastric decompression (nasogastric tube drainage).[14] Declare the patient nil by mouth.[14]

Initiate bowel decompression.

Place a nasogastric tube or long intestinal tube to decompress air/fluid in the upper gastrointestinal tract.[14][4] This may also prevent aerophagia and relieve nausea and vomiting.[15]
Follow your local protocol for this procedure. Remove the tube as the patient’s clinical condition improves and as nasogastric aspirates decrease.

Nasogastric tube insertion animated demonstration

How to insert a fine bore nasogastric tube for feeding.

Plus – emergency surgery and correction of underlying cause

Back

Plus –

emergency surgery and correction of underlying cause

Treatment recommended for ALL patients in selected patient group

Consult a general surgeon.[4][14] Operative treatment is indicated in patients with complete small bowel obstruction, peritonitis, or evidence of strangulation, and those who do not respond to non-operative treatment.

If you suspect ischaemia or strangulation, arrange for surgery as soon as possible, and definitely within 6 hours of the suspected onset of ischaemia or strangulation.[4]

Surgery is indicated in patients with adhesional obstruction if there are signs of peritonitis, hernia strangulation, or bowel ischaemia.[14]

In patients with complete small bowel obstruction, peritonitis will develop in time if not already present. For this reason, early surgical intervention is crucial whenever complete small bowel obstruction is suspected or diagnosed.

Computed tomographic evidence of a non-adhesional cause (tumour, hernia, volvulus, or gallstone) or evidence of bowel ischaemia is an indication for surgery.[4][11]

The most suitable procedure for the patient should be carefully selected.

Laparoscopic surgery is a possible alternative to open surgery if experienced surgeons are available, particularly if imaging has suggested a technically straightforward obstruction.[4]
- The main benefit of laparoscopic surgery compared with an open procedure seems to be a shorter length of hospital stay.[4][14][48][49]
- Laparoscopic surgery will not be suitable for all patients and it may be associated with a higher risk of bowel injury.[14]

Prior to surgery, identify and treat any correctable comorbidities so that surgery is not delayed.

Assess the patient’s bleeding and venous thromboembolism (VTE) risk prior to surgery.[53]
Use a validated VTE prophylaxis tool. The National Institute for Health and Care Excellence in the UK states that a commonly used risk assessment tool for surgical patients is the UK Department of Health VTE risk assessment tool.[53] Department of Health VTE risk assessment tool Opens in new window Follow your local trust protocol for thromboprophylaxis.
Arrange a group and save.
Reassess the risk of bleeding and venous thromboembolism at the point of consultant review or if the patient’s clinical condition changes.
Prescribe antibiotics according to your local protocol.

Use a risk score recommended by your local protocol, such as the National Emergency Laparotomy Audit (NELA) risk model in the UK, to calculate a patient’s morbidity and mortality risk before surgery.[16][54] NELA risk calculator Opens in new window This can be used as a way to explain the risks of surgery to patients and their relatives, which enables shared decision-making and informed consent.

Evidence: Selecting patients for a laparoscopic procedure

Laparoscopic procedures may be beneficial for selected patients with adhesive small bowel obstruction; however, the criteria are based mostly on evidence from non-randomised studies and the main benefit seems to be shorter length of hospital stay.

The World Society of Emergency Surgery (WSES) 2018 guidelines on adhesive small bowel obstruction discuss the pros and cons of treatment with laparoscopic versus open surgery in specific groups of patients.[14]

One systematic review of 14 non-randomised studies (published in 2016) found decreased morbidity, in-hospital mortality, and surgical infections. However, there was concern about strong selection bias with patients with less-severe adhesive small bowel obstruction being allocated to laparoscopy.
Careful selection of patients was recommended in the guideline as complications such as bowel perforation are likely to increase with very distended loops of bowel and multiple complex adhesions. The guideline cited three retrospective studies with bowel injury ranging from 6.3% to 26.9% in patients undergoing laparoscopic surgery for adhesive small bowel obstruction. A 2017 population-based study in 8584 patients also found an increased risk of bowel resection with laparoscopic procedures (53.5% versus 43.4%).
The guideline notes that laparoscopic surgery may be more difficult in people who have had previous radiotherapy.
The guideline also notes that non-operative treatment is effective in most patients with adhesive small bowel obstruction and should be tried prior to any surgical procedure unless there are signs of peritonitis, strangulation, or bowel ischaemia. (Weak recommendation based on one non-randomised study).

Subsequent to the WSES guideline, a multicentre, open label randomised controlled trial (RCT) was published in 2019.[48]

The RCT included non-pregnant patients (n=104) aged 18 to 95 years (median 73.5 years) with adhesive small bowel obstruction likely due to a single fibrous band that had not resolved with conservative management.
Length of postoperative hospital stay, the primary outcome, was shorter in the laparoscopic group (laparoscopic group 4.2 days versus open group 5.5 days).
There was no significant difference in postoperative complications or mortality (1 death in each group) at 30 days.
- Bowel recovery, duration of epidural catheterisation, and sick leave were all significantly better in the laparoscopic group.
A systematic review (search date May 2019) included this RCT along with 2 matched observational studies and 11 unmatched ones (n=37,007).[49]
- There were no significant differences between laparoscopic and open surgery in the primary analyses (matched studies only).
- In sensitivity analyses (all included studies), better outcomes were seen with laparoscopic surgery for postoperative mortality, length of postoperative hospital stay, operative time, time to flatus, severe postoperative complications, and early unplanned reoperations. See the study report for the full statistical analysis.
- The systematic review authors concluded that laparoscopic surgery is safe and feasible, although more research is required on selection criteria.

An earlier systematic review (published in 2009) quoted in the WSES guidelines states that the predictive factors for successful laparoscopic adhesiolysis are:[50]

Number of previous laparotomies ≤2 (because the number of laparotomies correlates with the severity of adhesions)
Previous paramedian surgical scar
Appendectomy as the previous surgical treatment causing adhesions
Single rather than multiple band adhesions (although this may not be known preoperatively)
Early laparoscopic management within 24 hours from the onset of symptoms (before the small bowel dilatation reduces the laparoscopic operating field)
No signs of peritonitis on physical examination
Experience of the surgeon.

The 2009 review also reported absolute contraindications for laparoscopy including:[50]

Abdominal film showing a >4 cm dilatation of small bowel
The presence of ischaemic or necrotic bowel, indicated by signs of peritonitis on physical examination (because in cases of peritonitis, intestinal resection and anastomosis could be needed and safely performed through open access)
Severe comorbidities: cardiovascular, respiratory, and haemostatic disease or haemodynamic instability (because they do not allow a safe pneumoperitoneum and require a short operating time).

Surgery is not indicated if the computed tomography scan demonstrates that the clinical scenario results from a functional problem (ileus – particularly postoperatively, pseudo-obstruction, diabetes, or opiate-related).[4]

Do not routinely use anti-adhesion products after surgery for adhesional obstruction.[4][11]

Adhesion barriers might be useful to prevent recurrence after surgical treatment of adhesional small bowel obstruction.[14]
However, the Royal College of Surgeons of England advises against their routine use after surgery for adhesional obstruction.[4][11]

Evidence: Use of anti-adhesion products after surgery for adhesional obstruction

Use of anti-adhesion products is not routinely recommended for secondary prevention of adhesions after surgery for adhesive small bowel obstruction.

Anti-adhesion products may help reduce recurrence of adhesive small bowel obstruction following surgical treatment; however, the evidence is contradictory. Most evidence is retrospective, low-quality, indirect evidence from studies of the use of anti-adhesion barriers in the primary prevention of adhesive small bowel obstruction.

In a randomised controlled trial (RCT) published in 2012, 181 patients with adhesive small bowel obstruction and a surgical indication for laparotomy were randomised to receive standard treatment or icodextrin 4% solution before the abdominal closure.[51]

In this RCT, the adhesive small bowel obstruction recurrence rate was 2.19% (2/91) in the icodextrin groups versus 11.11% (10/90) in the control group after a mean follow-up of 41.4 months (P <0.05).
Based on this RCT, the World Society of Emergency Surgery 2018 guideline makes a weak recommendation for the use of adhesion barriers to reduce the risk of recurrence.[14]

A systematic review (search date March 2015) found no other RCTs published or in progress at that time. The review authors commented on the safety and efficacy of anti-adhesion products based on the research in primary prevention of adhesions and from the above RCT. They concluded that reasons for poor uptake could include lack of awareness or doubt about cost-effectiveness (although they pointed towards studies that show routine use may be cost-effective).[52]

Royal College of Surgeons of England guidelines from 2014 state: “Current evidence does not support the routine administration of anti-adhesion products after surgery for adhesional obstruction”.[4] This is based on the 2012 Eastern Association for the Surgery of Trauma guideline, which considered evidence from two prospective studies in primary prevention that found no difference in small bowel obstruction with the use of a hyaluronate carboxymethylcellulose barrier, even though four retrospective studies (also in primary prevention) had shown a benefit.[11]

Advantages of liquid icodextrin 4% are its safety, low cost, and ease of use in both laparoscopic and open surgery. Disadvantages are that it may be better at preventing de novo adhesions as opposed to the reformation of previous ones. Hyaluronate carboxymethylcellulose might be more efficacious than icodextrin 4%, but this solid membrane barrier is less practical in laparoscopic surgery.[14]

Identify and treat the underlying cause of the bowel obstruction. Specific treatment may include appendectomy for appendicitis, tumour resection for obstructing tumour, and hernia repair for inguinal hernia.

Adhesions are the most common cause of small bowel obstruction.[55][56][57]

There may also be a role for non-surgical management. In patients with small bowel obstruction as a result of stricturing secondary to Crohn’s disease, endoscopic balloon dilation and double-balloon enteroscopy-assisted dilation are possible alternatives to surgery.[58][59] These are very difficult interventions that are only likely to be available in specialised units.

complete or complicated small bowel obstruction: surgery not indicated

1st line – supportive care

Back

1st line –

supportive care

Treat patients in the accident and emergency department with fluid resuscitation bowel decompression, and analgesia.[4]

Small bowel obstruction is a surgical emergency, with a high risk of morbidity and mortality if not managed correctly.
Appropriate intervention is crucial. If untreated, patients may develop progressive intestinal ischaemia, necrosis, and perforation.
Follow local protocols if there are signs of sepsis. See our topic Sepsis for more information.

Consult a general surgeon early.[4][14]

Assess the patient’s risk using appropriate risk prediction tools and your clinical judgement.[41]

Patients should have their risk of morbidity and mortality assessed and recorded in the medical records by a senior surgeon (CT3/ST3 or higher in the UK) within 4 hours of admission or transfer.[41]

Refer to a consultant and discuss ‘high-risk’ patients with a consultant within 1 hour.[16] Discuss the patient with the anaesthetic and critical care teams, if necessary.

A consultant review should take place in all patients diagnosed with acute bowel obstruction as soon as clinically indicated and at the latest within 14 hours of admission to hospital.
‘High risk’ is defined as where the risk of mortality is greater than 10%, or where a patient is unstable and not responding to treatment.[16]

Fluid resuscitation

Use intravenous fluids for patients with signs of shock or severe dehydration, or in patients unable to tolerate oral fluids.

Use an ABCDE approach to manage any patients with shock empirically. Ensure a patent airway and give oxygen if needed.

Treat the underlying cause as early as possible.
Escalate all patients with shock to a senior clinician.

See our topic Shock for full management recommendations.

Indicators that the patient may need urgent fluid resuscitation include:[13]

Systolic blood pressure less than 100 mmHg
Heart rate more than 90 beats per minute
Cold peripheries
Capillary refill time more than 2 seconds
Respiratory rate more than 20 breaths per minute
National Early Warning Score (NEWS2) of 5 or more ( NEWS2 Opens in new window)
Passive leg raising suggests fluid responsiveness.

Check local protocols for specific recommendations on fluid choice.

In these patients, administer fluid resuscitation and place a catheter to monitor urine output.[4][14]

Consider the requirements for insulin-dependent diabetes patients. Indications for a variable rate intravenous insulin infusion include patients with diabetes or hospital-related hyperglycaemia who can’t take oral food or fluid and where it’s not possible to adjust their usual insulin regimen.[42] For example, when:
- Vomiting
- Nil by mouth and the patient will miss more than one meal
- There is severe illness with a need to achieve good glycaemic control (such as with sepsis).
Get specialist advice from the diabetes team in these circumstances.

Fluid loss from vomiting, bowel wall oedema, and loss of absorptive capacity leads to dehydration and electrolyte imbalance (metabolic alkalosis).[40]

Use an intravenous fluid management plan with details of the fluid and electrolyte prescription over the next 24 hours, plus plans for assessment and monitoring.

This should be reviewed by an expert daily.[13]
- In this context, the UK-based National Institute for Health and Care Excellence defines an expert as a healthcare professional who has core competencies to diagnose and manage acute illness.[13]
Regularly monitor patients receiving intravenous fluids.[13]
- Clinical monitoring should include current status of:
  - NEWS2 ( NEWS2 Opens in new window)
  - Fluid balance charts
  - Weight.
- Laboratory investigations should include:
  - Full blood count
  - Urea
  - Creatinine
  - Electrolytes.

Seek expert help if patients have a complex fluid and/or electrolyte redistribution issue or imbalance, or significant comorbidity, such as:[13]

Gross oedema
Sepsis
Hyponatraemia or hypernatraemia
Renal, liver, and/or cardiac impairment
Postoperative fluid retention and redistribution
Malnourishment and refeeding issues.

Analgesia

Pain is one of the predominant symptoms. Assess pain at presentation and throughout the admission.[16]

Screening and monitoring

Correct electrolyte disturbances.[14] Electrolyte imbalances are associated with both small bowel obstruction and paralytic ileus.[15]

Monitor the patient using an early warning score, such as the NEWS2 score. NEWS2 Opens in new window It measures the following parameters:[46]

Respiration rate
Oxygen saturation
Systolic blood pressure
Pulse rate
Level of consciousness or new-onset confusion
Temperature.

Consider nutritional support if a patient has not eaten for 5 days and may not be able to resume their usual diet within the next 5 days.[47]

Attend to other medical conditions, if present, such as diabetes. Consider anticoagulation reversal if surgery is likely.[4]

Assess frailty using a score, such as the Rockwood frailty score.[16][24] Rockwood Clinical Frailty Scale Opens in new window

Discuss patients with a high frailty score with the multidisciplinary team.
Establish a treatment escalation plan and record resuscitation status.
Arrange a risk assessment, with input from critical care.[16]

Primary options

morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response

Plus – nasogastric decompression

Back

Plus –

nasogastric decompression

Treatment recommended for ALL patients in selected patient group

Prevent aspiration of vomit by gastric decompression (nasogastric tube drainage).[14] Declare the patient nil by mouth.[14]

Initiate bowel decompression.

Place a nasogastric tube or long intestinal tube to decompress air/fluid in the upper gastrointestinal tract.[4][14] This may also prevent aerophagia and relieve nausea and vomiting.[15]
Follow your local protocol for this procedure. Remove the tube as the patient’s clinical condition improves and as nasogastric aspirates decrease.

Nasogastric tube insertion animated demonstration

How to insert a fine bore nasogastric tube for feeding.

Plus – correction of the underlying cause

Back

Plus –

correction of the underlying cause

Treatment recommended for ALL patients in selected patient group

Adhesions are the most common cause of small bowel obstruction.[55][56][57]

incomplete small bowel obstruction or complete without complications

1st line – supportive care

Back

1st line –

supportive care

Treat patients in the accident and emergency department with fluid resuscitation bowel decompression, and analgesia.[4]

Small bowel obstruction is a surgical emergency, with a high risk of morbidity and mortality if not managed correctly.
Appropriate intervention is crucial. If untreated, patients may develop progressive intestinal ischaemia, necrosis, and perforation.
Follow local protocols if there are signs of sepsis. See our topic Sepsis for more information.

Consult a general surgeon early.[4][14]

Assess the patient’s risk using appropriate risk prediction tools and your clinical judgement.[41]

Patients should have their risk of morbidity and mortality assessed and recorded in the medical records by a senior surgeon (CT3/ST3 or higher in the UK) within 4 hours of admission or transfer.[41]

Refer to a consultant and discuss ‘high-risk’ patients with a consultant within 1 hour.[16] Discuss the patient with the anaesthetic and critical care teams, if necessary.

A consultant review should take place in all patients diagnosed with acute bowel obstruction as soon as clinically indicated and at the latest within 14 hours of admission to hospital.
‘High risk’ is defined as where the risk of mortality is greater than 10%, or where a patient is unstable and not responding to treatment.[16]

Fluid resuscitation

Use intravenous fluids for patients with signs of shock or severe dehydration, or in patients unable to tolerate oral fluids.

Use an ABCDE approach to manage any patients with shock empirically. Ensure a patent airway and give oxygen if needed.

Treat the underlying cause as early as possible.
Escalate all patients with shock to a senior clinician.

See our topic Shock for full management recommendations.

Indicators that the patient may need urgent fluid resuscitation include:[13]

Systolic blood pressure less than 100 mmHg
Heart rate more than 90 beats per minute
Cold peripheries
Capillary refill time more than 2 seconds
Respiratory rate more than 20 breaths per minute
National Early Warning Score (NEWS2) of 5 or more ( NEWS2 Opens in new window)
Passive leg raising suggests fluid responsiveness.

Check local protocols for specific recommendations on fluid choice.

In these patients, administer fluid resuscitation and place a catheter to monitor urine output.[4][14]

Consider the requirements for insulin-dependent diabetes patients. Indications for a variable rate intravenous insulin infusion include patients with diabetes or hospital-related hyperglycaemia who can’t take oral food or fluid and where it’s not possible to adjust their usual insulin regimen.[42] For example, when:
- Vomiting
- Nil by mouth and the patient will miss more than one meal
- There is severe illness with a need to achieve good glycaemic control (such as with sepsis).
Get specialist advice from the diabetes team in these circumstances.

Fluid loss from vomiting, bowel wall oedema, and loss of absorptive capacity leads to dehydration and electrolyte imbalance (metabolic alkalosis).[40]

Use an intravenous fluid management plan with details of the fluid and electrolyte prescription over the next 24 hours, plus plans for assessment and monitoring.

This should be reviewed by an expert daily.[13]
- In this context, the UK-based National Institute for Health and Care Excellence defines an expert as a healthcare professional who has core competencies to diagnose and manage acute illness.[13]
Regularly monitor patients receiving intravenous fluids.[13]
- Clinical monitoring should include current status of:
  - NEWS2 ( NEWS2 Opens in new window)
  - Fluid balance charts
  - Weight.
- Laboratory investigations should include:
  - Full blood count
  - Urea
  - Creatinine
  - Electrolytes.

Seek expert help if patients have a complex fluid and/or electrolyte redistribution issue or imbalance, or significant comorbidity, such as:[13]

Gross oedema
Sepsis
Hyponatraemia or hypernatraemia
Renal, liver, and/or cardiac impairment
Postoperative fluid retention and redistribution
Malnourishment and refeeding issues.

Analgesia

Pain is one of the predominant symptoms. Assess pain at presentation and throughout the admission.[16]

Screening and monitoring

Correct electrolyte disturbances.[14] Electrolyte imbalances are associated with both small bowel obstruction and paralytic ileus.[15]

Monitor the patient using an early warning score, such as the NEWS2 score. NEWS2 Opens in new window It measures the following parameters:[46]

Respiration rate
Oxygen saturation
Systolic blood pressure
Pulse rate
Level of consciousness or new-onset confusion
Temperature.

Consider nutritional support if a patient has not eaten for 5 days and may not be able to resume their usual diet within the next 5 days.[47]

Attend to other medical conditions, if present, such as diabetes. Consider anticoagulation reversal if surgery is likely.[4]

Assess frailty using a score, such as the Rockwood frailty score.[16][24] Rockwood Clinical Frailty Scale Opens in new window

Discuss patients with a high frailty score with the multidisciplinary team.
Establish a treatment escalation plan and record resuscitation status.
Arrange a risk assessment, with input from critical care.[16]

Primary options

morphine sulfate: 5-10 mg subcutaneously/intravenously/intramuscularly every 4 hours initially, adjust dose according to response

Plus – nasogastric decompression

Back

Plus –

nasogastric decompression

Treatment recommended for ALL patients in selected patient group

Prevent aspiration of vomit by gastric decompression (nasogastric tube drainage).[14] Declare the patient nil by mouth.[14]

Initiate bowel decompression.

Place a nasogastric tube or long intestinal tube to decompress air/fluid in the upper gastrointestinal tract.[14][4] This may also prevent aerophagia and relieve nausea and vomiting.[15]
Follow your local protocol for this procedure. Remove the tube as the patient’s clinical condition improves and as nasogastric aspirates decrease.

Nasogastric tube insertion animated demonstration

How to insert a fine bore nasogastric tube for feeding.

Consider – surgery and correction of underlying cause

Use of this content is subject to our disclaimer

Small bowel obstruction

complete or complicated small bowel obstruction: surgery indicated

supportive care

Fluid resuscitation

Analgesia

Screening and monitoring

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

nasogastric decompression

emergency surgery and correction of underlying cause

Evidence: Selecting patients for a laparoscopic procedure

Evidence: Use of anti-adhesion products after surgery for adhesional obstruction

complete or complicated small bowel obstruction: surgery not indicated

supportive care

Fluid resuscitation

Analgesia

Screening and monitoring

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

nasogastric decompression

correction of the underlying cause

incomplete small bowel obstruction or complete without complications

supportive care

Fluid resuscitation

Analgesia

Screening and monitoring

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

nasogastric decompression

surgery and correction of underlying cause

Small bowel obstruction

Treatment algorithm

complete or complicated small bowel obstruction: surgery indicated

supportive care

Fluid resuscitation

Analgesia

Screening and monitoring

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

nasogastric decompression

emergency surgery and correction of underlying cause

Evidence: Selecting patients for a laparoscopic procedure

Evidence: Use of anti-adhesion products after surgery for adhesional obstruction

complete or complicated small bowel obstruction: surgery not indicated

supportive care

Fluid resuscitation

Analgesia

Screening and monitoring

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

nasogastric decompression

correction of the underlying cause

incomplete small bowel obstruction or complete without complications

supportive care

Fluid resuscitation

Analgesia

Screening and monitoring

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

nasogastric decompression

surgery and correction of underlying cause