• It is always worth performing a rectal examination to rule out constipation before confirming a diagnosis of intestinal obstruction.
• Development of malignant bowel obstruction can be a slow and insidious process with episodes of paralytic ileus and mechanical obstruction over days to weeks.
• Careful assessment of the clinical symptoms/signs is essential for the most appropriate management.
• Paralytic ileus (e.g. electrolyte disturbance or autonomic dysfunction) may mimic intestinal obstruction but is potentially reversible. Colic is usually not a feature in such patients and clinical examination may reveal absence of or reduced bowel sounds.
• Mechanical intestinal obstruction (e.g. as a result of adhesions or tumour) will usually present with colic and clinical examination may reveal increased bowel sounds. This can generally be divided into:-
  • Subacute or partial obstruction (intermittent symptoms of colicky abdominal pain, nausea and vomiting, reduced frequency of passing flatus and opening bowels) which may resolve for a limited time
  • Complete obstruction (sustained symptoms of colicky abdominal pain, nausea and vomiting and absence of flatus and stool) which is irreversible
• Surgical intervention or stenting may be helpful for a small number of patients. A palliative bypass with or without stoma formation may be indicated if there is single level obstruction. Diffuse intra-abdominal disease or ascites are contraindications for palliative surgery.
• The main principles of management are to control nausea, colic and other abdominal pain using drugs shown in the Section: Syringe Driver 
• It is possible to keep a patient’s symptoms controlled with subcutaneous medications given via a syringe driver/pump. Some patients may prefer occasional vomits (as long as nausea is well controlled) to avoid naso-gastric tube (NGT) insertion. Other patients with obstruction and large volume vomiting may prefer NGT insertion to avoid persistent vomiting.
• Dry mouth can be managed with regular oral care and ice cubes to suck
• Intravenous or subcutaneous fluids may be considered if the patient is dehydrated and thirsty
• In partial malignant obstruction the combination below can be effective in restoring bowel function:-
  • Metoclopramide and dexamethasone (See Chapter: Corticosteroids)

Do not use metoclopramide in patients with intestinal colic and in those with Parkinson’s spectrum disorders.

• When complete intestinal obstruction occurs, prokinetic agents and bulk-forming or stimulant laxatives are contra-indicated.
• Patients may be able to tolerate small amounts of food and drink, if the nausea is well controlled. A low residue diet may be better tolerated (soft low fibre foods)