When should I consider referring an adult patient with constipation for further investigation?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Consider referring an adult patient with constipation for further investigation if:

  • There are features suggestive of bowel obstruction such as known intra-abdominal tumour, absence of passage of flatus, nausea and vomiting, colicky abdominal pain, abdominal distension or tenderness, or abnormal bowel sounds.
  • There is unexplained weight loss, abdominal pain, rectal bleeding, iron deficiency anaemia, or changes in bowel habit, especially in patients aged 40 years and over.
  • There is a palpable rectal or abdominal mass.
  • The diagnosis remains uncertain after primary care assessment, particularly if common causes have been excluded or if symptoms are severe or persistent despite initial management.
  • There are signs or symptoms that raise suspicion of colorectal cancer or other serious pathology, warranting a suspected cancer pathway referral.
  • There is a need to exclude underlying treatable conditions such as metabolic or endocrine disorders (e.g., thyroid dysfunction, hypercalcaemia) through blood tests.

Before referral, an abdominal and rectal examination should be performed to assess for causes and exclude obstruction, unless contraindicated (e.g., in chemotherapy patients).

Referral is also appropriate if constipation is severe, persistent, or associated with significant impact on quality of life and has not responded to initial management.

These recommendations are based on expert consensus and NICE guidance on suspected cancer and palliative care constipation management.

References: ,

Educational content only. Always verify information and use clinical judgement.