Colonoscopy

What it involves

Colonoscopy is an examination of the inside of the large intestine with a flexible endoscope passed through the anus. We assess the rectum and the colon as far as the caecum, and often also the ileocaecal valve and the final part of the small intestine. We can see redness, friability and ulceration of the mucosa, polyps, tumours, strictures and parasites — changes that ultrasound usually does not show.

Biopsies are the key: through the endoscope channel we take a dozen or so small samples from different segments of the intestine, including where the mucosa looks normal, because microscopic changes can be invisible. Histopathology distinguishes chronic inflammation of the large intestine from lymphoma, detects granulomatous inflammation in a boxer or French bulldog, and determines the treatment.

We perform the examination under general anaesthesia with monitoring; we often combine it with gastroscopy under the same anaesthetic when the signs suggest disease of the whole digestive tract.

When it is used

We recommend colonoscopy for diarrhoea with large-bowel features — frequent, small portions of stool with mucus and fresh blood, straining, painful defecation — lasting more than 3–4 weeks despite diet, antiparasitic treatment and trial treatment, and also when polyps or a rectal tumour are suspected, for a bowel stricture, a lesion felt on rectal examination or recurrent rectal prolapse.

In young dogs of predisposed breeds with bloody diarrhoea and weight loss, the examination is worth doing early, because some forms of colitis require treatment targeted at specific bacteria.

Indications: symptoms that should prompt a visit

• A dog passes stool many times a day, in small portions, with mucus and drops of fresh blood.
• The animal strains and arches during defecation, sometimes unsuccessfully, and then passes loose stool.
• Diarrhoea returns every time medication is stopped or the diet is changed.
• A cat has chronically loose stool with blood and is losing weight despite a good appetite.
• On rectal examination the veterinarian felt a nodule or an irregularity of the intestinal wall.
• A young boxer or French bulldog has persistent bloody diarrhoea and is losing weight.
• The stool is as thin as a pencil — a bowel stricture is suspected.

Conditions for which we use it in particular

Diagnostics beforehand

Before colonoscopy we perform a faecal examination (parasites, Giardia, culture where indicated), a blood count, biochemistry, a rectal examination and an abdominal ultrasound with assessment of the thickness of the intestinal wall and the lymph nodes. Often we first run a diet trial and antiparasitic treatment — if the signs resolve, endoscopy is not needed.

Pre-anaesthetic assessment under STD-01. Preparing the bowel is key: for 24–36 hours before the examination a liquid diet or fasting (according to the instructions), and on the day before and in the morning, enemas with warm water or a laxative solution — a dirty bowel makes assessment and biopsies impossible. You will receive the exact plan in writing.

How it proceeds

Aftercare

In the evening give a small portion of easily digestible food. For 1–3 days bloating (from the air used in the examination), mucus or a small amount of blood in the stool and slight straining are possible — this is normal after biopsies. Continue the current medication unless agreed otherwise.

We discuss the histopathology result after 7–14 days and agree the treatment: diet, anti-inflammatory or immunomodulatory drugs, a targeted antibiotic for histiocytic inflammation, oncological treatment or surgery. Call if heavy bleeding, severe abdominal pain, vomiting, fever or loss of appetite for more than a day appears.

Frequently asked questions