Constipation Flashcards
List four mechanisms of constipation.
Abnormal bowel peristalsis
Hard faeces
Bowel obstruction
Patient not able/willing to push
For each of the mechanisms below, list some causes of constipation: Abnormal bowel peristalsis Hard faeces Bowel obstruction Patient not able/willing to push
- Abnormal bowel peristalsis IBS Medications Others: hypothyroidism, hypercalcaemia, hypokalaemia, diabetic neuropathy, multiple sclerosis, Parkinson’s disease - Hard faeces Lack of dietary fibre Dehydration - Bowel obstruction Colorectal carcinoma Sigmoid volvulus - Patient not able/willing to push Haemorrhoids Anal fissure Pelvic floor dysfunction
List some red flag symptoms that may suggest that the constipation has a sinister cause.
Severe constipation that’s unresponsive to treatment
Absolute constipation
Rectal bleeding, tenesmus or intermittent mucoid diarrhoea
Significant weight loss, iron deficiency anaemia, night sweats
Why is it important to ask about the time course of the constipation?
Chronic constipation – usually benign
Recent change – pathology
Describe the type of stools that will be passed in constipation caused by dehydration or a lack of dietary fibre.
Hard and lumpy
List some associated symptoms of constipation.
Weight loss, night sweats, fever Diarrhoea Tenesmus Blood in stools Bloating Hypothyroid symptoms (cold intolerance, weight gain, reduced appetite) Bone pains Polyuria and polydipsia
What might intermittent diarrhoea with constipation suggest?
Young – IBS
Middle-aged – colorectal cancer
Elderly – diverticular disease
What is tenesmus and what does it indicate?
Sensation of having a desire to defecate, which is continuous and recurs frequently, with or without the production of significant amounts of faeces
Suggests that there is a persistent mass in the rectum
Why is it important to take note of any bone pains that the patient is complaining about?
This may indicate the presence of bone metastases, which can lead to hypercalcaemia, which, in turn, can cause constipation
List some major risk factors for constipation.
Past medical history of bowel disease, neurological disorders, back problems or endocrine disease
Family history of bowel disorders
Medications
Diet
List some hereditary disorders that are risk factors for constipation.
Familial adenomatous polyposis (FAP)
Hereditary non-polyposis colorectal cancer (HNPCC)
Peutz-Jeghers syndrome
List some classes of medication that are known for causing constipation.
Opiates Calcium channel blockers Iron supplements Tricyclic antidepressants Anticholinergics
List some features of the abdominal examination that could give clues about the aetiology of the constipation.
Virchow’s lymphadenopathy Abdominal mass Anal fissures or haemorrhoids Mass on DRE Lax anal tone
List some important blood tests that may be useful when investigating a patient with constipation.
FBC – colonic cancers can bleed causing anaemia
U&Es and calcium – check for hypokalaemia and hypercalcaemia
TFTs – check for hypothyroidism
Glucose and HbA1c – check glycaemic control to assess risk of diabetic neuropathy
FOBT is used as a screening test for colorectal cancer. Other than colorectal cancer, what else can give a positive FOBT?
Colonic angiodysplasia
Polyps
Haemorrhoids
Aspirin, warfarin etc.
