Concise summary of the Gastrointestinal System

Chapter 1 – GI System



CROHN’S DISEASE
Chapter 1 – Gastro-
 Chronic, inflammatory bowel disease
Intestinal System
characterised by thickened areas of the GI
wall with inflammation extended through all
COELIAC DISEASE layers, deep ulceration and fissuring of
mucosa and presence of granulomas
 Define – autoimmune condition linked with
 May present as recurrent attacks, with acute
chronic inflammation of small intestine.
exacerbations
 Dietary proteins like gluten (present in wheat,
 CD is a cause of secondary osteoporosis
barley and rye) activate an abnormal immune
 Symptoms = depend on site of disease. Incl.
response in intestinal mucosa, leading to
abdominal pain, diarrhoea, fever, weight loss,
malabsorption of nutrients
rectal bleeding
 Aims = reduce symptoms and complications
 Complications = intestinal strictures, anaemia,
Treatment abscesses in intestinal wall, fistulae,
 Strict, life-long, gluten-free diet malnutrition, colorectal and small bowel
 Avoid medicating with OTC vitamins or cancers, growth failure and delayed puberty
mineral supplements in children
 Consider risk of osteoporosis  Extra-intestinal manifestations = arthritis and
 Refractory coeliac disease = prednisolone abnormalities of joints, eyes, liver, skin
 Aims = induction and maintenance of
DIVERTICULAR DISEASE AND remission and relief of symptoms
DIVERTICULITIS
Fistulating CD – complication involving formation
Diverticular disease – condition where diverticula of a fistula between intestine and strictures like
cause intermittent lower abdominal pain in perianal skin, bladder and vagina
absence of inflammation or infection
Non-Drug Tx = smoking cessation, nutrition
Diverticulitis – occurs when diverticula become
Drug Tx – Monotherapy
inflamed and infected, causing marked lower
1. Corticosteroid (prednisolone,
abdominal pain, fever, general malaise and large
methylprednisolone) – to induce remission in
rectal bleeds. Complications include episodes
Pts with a 1st presentation or single
associated with an abscess, free perforation,
exacerbation in a 12-month period
fistula, obstruction or stricture
2. Budesonide or aminosalicylate
Treatment (sulfasalazine, mesalazine) – if (1)
 High-fibre diet is advised inappropriate or Pt has distal ileal, ileocecal or
 Low residue diet plus bowel rest right-sided colonic disease
 Antibacterials – when infection occurs, or Pt is
Drug Tx – Add-On Treatment
immunocompromised
 Given if there’s >2 inflammatory
 Elective surgery – for symptomatic relief or to
exacerbations in a 12-month period or the
prevent recurrence (including from
corticosteroid dose cannot be reduced
complications like those above)
1. Azathioprine or mercaptopurine – to induce
remission
2. Methotrexate – if (1) is inappropriate or
thiopurine methyltransferase (TPMT) activity
is deficient

, Chapter 1 – GI System


3. Adalimumab, infliximab or vedolizumab – for Distal inflammation = use a rectal prep (if
severe, active CD inflammation is extended, consider systemic)

Maintenance of Remission Diarrhoea with UC = anti-diarrhoeals like
1. Azathioprine or mercaptopurine – to loperamide or codeine – AVOID in acute UC like
maintain remission when used previously with toxic megacolon
a corticosteroid to induce remission
Proximal faecal loading in proctitis = macrogol-
2. Methotrexate – to maintain remission in Pts
containing osmotic laxative
who’ve used MTX for inducing remission or
who cannot tolerate (1) Treatment of acute mild-to-mod UC
3. Post-surgery – consider (1) or 1. Acute Tx to induce remission =
aminosalicylates aminosalicylate +/- corticosteroid
 AVOID corticosteroids and budesonide 2. Acute, mild-to-mod extensive UC = oral and
rectal aminosalicylates
Other Treatments
3. Mild-to-mod initial presentation or
 Loperamide or codeine – diarrhoea (if colitis is
inflammatory exacerbation =
NOT present)
aminosalicylates or rectal corticosteroid
 Colestyramine – diarrhoea
4. Subacute proctitis/proctosigmoiditis = oral
Treatments for Fistulating CD prednisolone
 If symptomatic – consider drainage/surgery 5. Left-sided or extensive UC = high induction
 Metronidazole or ciprofloxacin – the former is dose of an oral aminosacylate +/- rectal
given for 1 month but max 3 months due to aminosalicylate or oral beclomethasone
risk of peripheral neuropathy
Initial Tx failure in mild-to-mod disease
ULCERATIVE COLITIS 1. No improvement in 4 weeks = add oral
prednisolone
 Chronic, life-long, inflammatory condition 2. No improvement in 2-4 weeks with
with diffuse mucosal inflammation in a prednisolone = oral tacrolimus
relapsing-remitting pattern
 Prevalence – between 15-25 years Treatment of acute, severe UC
 Symptoms = bloody diarrhoea, urgent need to 1. Acute, severe UC = medical emergency!
defecate and abdominal pain 2. Induce remission in acute, severe UC while
 Complications = colorectal cancer, VTE, assessing for surgery = IV corticosteroids +/-
secondary osteoporosis, toxic megacolon IV ciclosporin

Monoclonal antibodies for acute UC =
- Proctitis – inflammation of rectum adalimumab, golimumab, infliximab, vedolizumab
- Proctosigmoiditis – inflammation rectum and
sigmoid colon Maintaining remission in UC
- Left-sided colitis – involves colon distal to 1. To reduce relapse risk = aminosalicylates
splenic flexure (single daily doses are more effective)
- Extensive colitis – affects the colon proximal 2. If there’s >2 exacerbations in 12-months =
to splenic flexure and includes pan-colitis oral azathioprine

Drug Tx IRRITABLE BOWEL SYNDROME
 Severity is classified as mild, moderate or
 Chronic, relapsing, life-long condition usually
severe using the Truelove and Witts’ Severity
affecting 20-30 year olds
Index to assess bowel movements, heart rate,
 Symptoms = abdominal pain or discomfort,
erythrocyte sedimentation rate and presence
disordered defecation (D or C with straining,
of pyrexia, melaena, anaemia