Constipation Flashcards
What is constipation?
stool that is passed infrequently and/or with difficulty
What do you have to clarify with constipation and patients?
what patient means by constipation: write in notes about frequency, ease of passage and volume
What 4 things are needed for normal defecation?
- Adequate bowel peristalsis
- Relatively soft feaces
- No obstruction to outflow
- Will and ability to push
What are the abnormal bowel peristalsis reasons for constipation?
- IBS
- Medications (e.g. opiates, iron supplements, CCBs)
- Hypothyroidism
- Hypercalcaemia
- Hypokalaemia
- MS
- Parkinson’s
- Diabetic neuropathy
- Idiopathic megascolon
- Idiopathic slow trasnit
What are the hard feaces reasons for constipation?
- Lack of dietary fibre
2. Dehydration
What are the bowel obstruction reasons for constipation?
- Colorectal adenocarcinoma
- Sigmoid Volvus
- Other pelvic masses (e.g. uterine fibroids, ovarian tumour)
- colonic strictures (e.g. radiotherapy, Crohn’s disease, diverticular disease)
What are the patient not pushing reasons for constipation?
- Haemorrhoids
- Anal fissue
- Pelvic floor dysfunction (e.g. after hysterectomy)
What non medical reasons are there for constipation?
- due to uncomfort of hospital
- if immobile (e.g. spinal pathology, old age) prone to constipation
What are the 6 red flags of constipation?
- Severe persistent constipation that is unresponsive to treatment
- Absolute constipation, i.e. not passing either stool or flatus
- Rectal bleeding, tenesmus, or intermittent mucoid diarrhoea
- Significant weight loss, iron deficiency anaemia, and/or night sweats
- PMHx of UC or colonic polyps
- Strong FHx of colon cancer or colonic polyps, particularly if affected family members were <60y
What questions do you ask about the constipation?
- characterise what patient means by constipation
2. when did it start
What would being constipated with passing hard, lumpy stool suggest?
lack of fibre or dehydration but no obstruction
What would constipation with no feaces or flatus suggest?
obstruction
What does recent change in bowel habit suggest?
pathology
What would chronic constipation suggest?
usually benign cause
What are associated symptoms of constipation should you ask about?
- Weight loss, night sweats, fever
- Diarrhoea
- Tenesmus
- Blood on feaces, per rectum or when wiping
- Bloating
- Feeling cold, reduced appetite, gaining weight
- Bone pain?
- Polyuria, thirst
- Note any abdominal pain
What could weight loss, night sweats, fever with constipation suggest?
malignancy
What could intermittent constipation and diarrhoea suggest?
- IBS (younger patients)
- Colorectal cancer (>45 years and diarrhoea mucoid)
- Diverticular disease (>60 years + episodes of LIF pain)
What would tenesmus and constipation suggest?
persistent mass in rectum
What could blood on feaces, per rectum or when wiping with constipation suggest?
- heamorrhoids
- anal fissure
- diverticular disease
- colorectal cancer
What could bloating and constipation suggest?
IBS
What could feeling cold, reduced appetite, gaining weight and constipation suggest?
hypothyroidism
What could bone pain and constipation suggest?
bone metastases which lead to hypercalcaemia that can cause constipation
What could polyuria, thirst and constipation suggest?
hypercalcaemia
What are the risk factors for constipation?
- Hx of bowel disease, neurological disorders, back problems or endocrine disease
- FHx of bowel disease
- MHx
- Diet
What FHx of bowel disease is relevant for constipation?
esp if increase chance of colorectal cancer, FAP, HNPCC or Peutz-Jegher’s disease
What medications can cause constipation?
- opiates
- anticholinergics
- tricyclic antidepressants
- CCB
- iron supplements
How do you ask a patient about their diet and hydration status?
healthy, varied, fibre rich, adequately hydrated - colour of urine
What do you look for on general inspection with constipation?
- Cachexia
2. Signs of hypothyroidism
What could cachexia suggest?
malignancy
What are some signs of hypothyroidism?
- loss of hair (esp outer third of eyebrow)
- brittle hair
- dry skin
- puffy eyes
- malar flush
What do you look for on abdominal exam for constipation?
- Virshow’s node (left supraclavicular fossa) enlargement
- Abdominal Mass
- Anal Fissure or Heamorrhoids
- Mass on DRE
- Lax anal tone
What would Virshow’s node enlargement with constipation suggest?
GI malignanacy
What could an abdominal mass with constipation be?
- impacted feaces
- colonic tumour
- Chrohn’s mass
- an ovarian mass
Why is it important to check for anal fissure or haemorrhoids?
may explain constipation (as too painful to push) - hard to know which came first
What would a mass on DRE with constipation suggest?
- rectal carcinoma
2. impacted feaces
What would a lax anal tone with constipation suggest?
neurological pathology e.g. diabetic neuropathy or MS
When do you do a neurological exam with constipation?
if history is suggestive of diabetic neuropathy, MS, cord compression or parkinsonism
What blood tests do you order if there is no obvious diagnosis from exam and history or constipation?
- FBC
- Electrolytes and calcium
- Thyroid function tests
- Glucose and HbA1c
Why do you order a FBC for constipation?
colonic mass can bleed causing aneamia
Why do you check electrolytes and calcium with constipation?
hypokalaemia and hypercalcaemia can cause constipation
Why do you do thyroid function tests with constipation?
exclude hypothyroidism
Why do you do glucose and HbA1c with constipation?
if diabetic can check control at present and a few months ago
What special tests can you order for constipation if they are suggested?
- Feacel occult blood test (FOBT)
2. Carcinoembryonic antigen (CEA)/CA19-9/CA125
What is the FOBT used for?
screen for asymptomatic colon cancer
Apart from colon cancer why else may you have feacal blood?
- angiodysplasia
- colonic polyps
- headmorrhoids
- aspirin
- warfarin
What must you do before a FOBT?
antiplatelets should be stopped 7 days before if poss
Is the FOBT useful?
test has low specifity and sensitivety for colon cancer, but a positive test warrants further investigations
Why do you look for carcinoembryonic antigens (CEA)/CA19-9/CA125?
markers of colon cancer
Are carcinoembryonic antigens (CEA)/CA19-9/CA125 useful?
lack specificity and sensitivity so not used to diagnose malignancy
What are carcinoembryonic antigens (CEA)/CA19-9/CA125 used for?
- monitor response
- relapse
- reccurence
- in patients with confirmed GI cancer
What imaging can b used for iron deficiency anaemia in context of change in bowel habit (constipation)?
- Protoscopy
- Rigid sigmoidoscopy
- Flexible sigmoidoscopy
- Colonoscopy
- CT colonogrpahy
- Double contrast barium enema (DCBE)
- OGD
What is a protoscopy?
transparent dilator used to visualise anus and rectum - done in clinic or wards
What are a rigid sigmoidoscopy?
visualises as far as sigmoid colon - done in clinic or wards
How is a flexible sigmoidscopy undertaken?
sedeation + enema
What is a flexible sigmoidoscopy used for?
- visualise as far as splenic flexture
2. used to take biopsies and remove small polyps
Is a flexible sigmoidscopy better than colonscopy?
FS misses 40% of tumours beyond splenic flexture so unless lots of other comorbidities, colonsopy if suspected cancer instead
How is a colonscopy different from felxible sigmoidoscopy?
more thorough bowel preperations + can visualise far as ileoceacal valve
What is CT colongraphy?
ct abdo after bowel preparation and insufflation
What does CT colongraphy show?
bowel lumen and surrounding structures (e.g. liver and ovaries)
When is a CT colongraphy used?
patients frail and unlikely to tolerate colonscopy and/or sigmoidoscopy
What is a double constrast barium enema?
- barium enema given to patients and plain radiographs taken at different times 2. lumen of bowel can be visualised
- rarely used
What is an OGD?
endoscope inserted via mouth and used to visualise as far as duodenum
When is an OGD used?
iron deficiency anaemia to exclude up GI source of blood loss
Where does colon cancer usually spread?
- liver and lungs
- ovaries in women
- lymphnodes draining colon
What imaging is used to stage colon cancer?
- combined CT chest abdo and pelvis with contrast
2. PET scan can be used for mets
What additional imaging can be used for rectal tumours?
MRI for local staging and if that is contraindicted, endorectal US used
