Infective and Other Colitis 

Colitis has many different causes although in many cases this is not clear. Where the cause remains unknown (or idiopathic) the term inflammatory bowel disease is used and encompasses the conditions of Ulcerative Colitis and Crohn’s disease. When the cause is known a number of common condtions are recognised. Their symptoms are usually similar and are:

• Diarrhoea usually bloody with mucous
• Abdominal pain
• Fever
• Shock and circulatory collapse due to dehydration and bowel perforation with peritonitis

Other types of Colitis 

Infective Colitis

Worldwide the most common cause. They are usually easily diagnosed with microbiological examination of the stool or blood.

• Salmonella
• Shigella
• Campylobacter
• E Coli
• Cholera
• Clostridium Difficile
• Tuberculosis
• Amoebic Dysentry
• Giardiasis
• Rotavirus

They are treated with supportive care, rehydration, antibiotics and occasionally surgery.

Ischaemic Colitis

Deficient blood and oxygen supply (ischaemia) to the colon results first in injury to the lining of the bowel (mucosa) then the whole bowel wall. The left side of the colon is most commonly affected. It is usually caused by narowing or blockage of the arteries of the bowel although poor blood flow throughout the body as a whole may be responsible. Occasionally it may be caused by other abdominal surgery.Treatment is with hydration, antibiotics, oxygen therapy and if this fails surgery.

Radiation Colitis or Proctitis

Radiation is used to treat a number of malignant conditions of the pelvic organs, most commonly prostate cancer. Frequently after such treatment rectal bleeding and alteration to bowel habit may occur. This may occur around the time of treatment (and usually resolves spontaneously in weeks) or may occur unpredictably many years later requiring treatment. It results from injury to the lining (mucosa) of the rectum caused by radiation “scatter” away from the intended site of treatment. Radiation causes injury to small blood vessels (arteritis) in the bowel mucosa, they become weak walled and easily damaged.

Symptoms are predominantly bleeding (usually bright red in colour) but also include diarrhoea, mucous discharge and tenesmus (a constant feeling of wishing to defaecate). Very rarely fibrosis (scarring) and narrowing of the rectum may occur.

Patients should always have endoscopic examination of their bowel performed (flexible sigmoidoscopy and colonoscopy) and a biopsy of the affected area.

Treatment is often required for symptoms that occur sometime after radiation therapy and its complexity is tailored to the severity of symptoms. Some patients will need nothing more than an examination and reassurance that occasional bleeding is not caused by a dangerous condition. When needed treatments may be defined as local (topical), endoscopic or surgical.

Local
Enemas or suppositories of:

• Sucralfate, Steroids, Mesalazine and Metronidazole

Endoscopic
Argon beamer coagulation during colonoscopy.

Surgery
Rectal instillation with formaldehyde under general anaesthetic.

Using these techniques symptoms can usually be settled but on occasion repeated or prolonged courses of treatment may be needed.