An Approach to Colitis
Doctor, I have bloody diarrhoea and abdomina pain! It is not getting better!
Introduction
Differential Diagnosis
Evaluation Priorities
Management Algorithms
Context: Emergency Unit
Introduction
Diarrhoea reflects the passage of loose or watery stools, typically at least three times in a 24-hour period. The following definitions have been suggested according to the duration of symptoms:
- Acute - 14 days or fewer in duration
- Persistent diarrhoea - more than 14 but fewer than 30 days in duration
- Chronic - more than 30 days in duration
- Invasive diarrhoea, or dysentery = diarrhoea with visible blood or mucus, commonly associated with fever and abdominal pain.
Most cases of acute diarrhoea in adults are of infectious aetiology and resolve with symptomatic treatment alone. Surgeons are seldom consulted for this symptom unless there is a diagnostic concern about the possibility of colitis - these patients are generally unwell and have symptoms of DYSENTERY.
Differential Diagnosis
There are multiple diagnoses to consider, and unless you use a structured approach the clinical scenarios can feel overwhelming.
It is practical to consider a diagnostic algorithm that starts with a broad range of conditions, and narrows down to the ones most pertinent to a surgical unit - patients with features of severe colitis are the ones you will need to manage, often in conjunction with a gastroenterologist.
Symptoms and Signs
Colitis implies inflammation of the colon.
| Colitis | Frequent passage of loose stool with/without mucus and blood, abdominal discomfort |
| Proctitis | Tenesmus is a characteristic symptom of inflammation of the rectum |
| Abdominal pain | Common in severe colitis |
| Examination findings | Pyrexia - infective colitis Abdominal tenderness common Distention = colonic dilatation in severe colitis or with obstruction Peritonism - indicative of impending perforation |
Differential Diagnosis
Common | Clues |
Infective Colitis (salmonella) | Severe dysentery, & abdominal pain, high pyrexia |
| Amaebic colitis | - |
| Clostridium difficile | Recent use of antibiotics |
| Ulcerative colitis | Intermittent diarrhoea and proctitis, +family Hx, intermittent, loss of weight, episcleritis, erythema nodosum or pyoderma gangrenosum, arhrtitis, PSC |
Uncommon and weird | Clues |
Ischaemic colitis | Vasculopath |
| Drug-induced | Recent chemotherapy, methotrexate |
| CMV | HIV +patient, severe immunocompromise |
| Intussusception | Younger patient, bloody diarrhoea, small bowel obstruction, palpable mass |
| Diversion colitis | Proximal stoma, usually mild colitis in the diverted segment |
| Diverticultis @ colitis | Acute diverticulitis, an elderly patient |
| Colonic Crohn’s disease | Rectum usually spared |
| Radiation colitis | Recent pelvic radiation, often for gynaecological cancer |
Other infections | Salmonella, Shigella, Campylobacter, Yersinia, Cryptosporidium |
Don't want to miss | Clues |
Colorectal cancer with obstruction | Symptoms of bloody/mucous loose stool, and massively distended proximal colon, particularly caecum. Incorrect medical Rx as a "colitis" will result in perforation and death |
Evaluation Priorities
How bad is this?
| Mild | Four or fewer stools per day with or without blood, no signs of systemic toxicity, and a normal erythrocyte sedimentation rate (ESR). Mild crampy pain, tenesmus, and periods of constipation are also common, but severe abdominal pain, profuse bleeding, fever, and weight loss are not part of the spectrum of mild disease. |
| Moderate | Frequent loose, bloody stools (>4 per day), mild anaemia not requiring blood transfusions, and abdominal pain that is not severe. Patients have minimal signs of systemic toxicity, including low-grade fever. Adequate nutrition is usually maintained, and weight loss is not associated with moderate clinical disease. |
| Acute Severe Colitis | Typically have frequent loose, bloody stools (>6 per day) with severe cramps and evidence of systemic toxicity as demonstrated by a fever (temperature >37.8oC), tachycardia (HR >90 beats/minute), anaemia (haemoglobin <10.5g/dL), or an elevated ESR or CRP (>30mm/hour). Patients may have rapid weight loss. |
What could go wrong? These are the complications of colitis
| Bleeding | Bleeding may be severe in up to 10% of patients. Massive haemorrhage occurs in up to 3% of patients and may necessitate urgent colectomy |
| Toxic megacolon | Fulminant colitis => 10 stools per day, continuous bleeding, abdominal pain, distention and acute, severe toxic symptoms including fever and anorexia. Toxic megacolon = colonic diameter >6cm or cecal diameter >9 cm and the presence of systemic toxicity |
| Perforation | Commonly occurs as a consequence of toxic megacolon. Perforation with peritonitis has been associated with 50% mortality in patients with ulcerative colitis |
Management Algorithms
The great majority are managed symptomatically with drugs targeted to the cause of colitis, typically either antibiotics or immunosuppression. Colitis is managed primarily by medical gastroenterologists in conjuction with a surgeon.
The key role of the surgeon is to identify the patients at risk of colonic perforation (i.e. patients with toxic megacolon) and operate on them BEFORE a perforation occurs. This would typically mandate a total or subtotal colectomy, with an ileostomy. Patients with acute severe colitis can look surprisingly well but have a high risk of perforation. The management of these patients is challenging and the decision to operate is difficult. Patients with acute severe colitis should be managed in a tertiary hospital setting or at least in consultation with a medical gastroenterologist.
The decision to intervene requires early referral to surgery, regular clinical examinations by the same team, senior clinical input, and much judgement. Patients on immunosuppression are particularly challenging, as the clinical signs of pyrexia, and peritonism can be masked by the medications.