Case history

After routine blood tests had been taken this 69 year old woman was found to have microcytic, hypochromic anaemia. Her general practitioner could not find any obvious cause and asked for further investigations.

Questions

(1) What procedure has this patient undergone and what radiological abnormalities can you identify?
(2) Estimate the relative dose of radiation from this radiological procedure compared with a posterior-anterior chest radiograph.
(3) What are the potential complications of the benign pathology seen on the film?
(4) If you suspected that this patient had a perforated bowel how would your radiological approach change? On further questioning by the consultant physician the patient admitted to otherwise unidentified symptoms of altered bowel habit and some pain in the abdomen, especially in the left iliac fossa.
(5) Given the findings seen on the radiograph what else might you consider doing?

Answers

(1) A double contrast barium enema has been carried out. This means that a mixture of barium (a radio-opaque contrast agent) and air has been used. This provides a better image of the fine detail of the bowel mucosa.
There are two main radiological abnormalities. A bowel stricture can be seen just proximal to the rectosigmoid junction. There is "shouldering" of this lesion with loss of the normal mucosal detail. There is also an abrupt change from normal to abnormal mucosa, which suggests a neoplastic stricture. There are also multiple diverticula in the sigmoid colon. Ninety per cent of diverticular disease is identified incidentally, as it is frequently asymptomatic in nature.

(2) A barium enema has the same radiation dose as 350 posterior-anterior chest radiograms. This is equivalent to three years of background radiation. You should be aware of radiation doses when ordering radiological procedures.

(3) The diverticular disease is the benign disease in this case, but several complications may occur. These include haemorrhage, abscess formation, fistula formation (with neighbouring bowel, vagina, or bladder), large bowel obstruction (caused by fibrotic stricturing), and bowel perforation.

(4) Administering barium is dangerous in cases of perforation as it may leak from the bowel - for example, perforated diverticulum - into the peritoneum. A water soluble agent, such as astrografin, will be required as this is safe and allows the bowel to be seen.

(5) You should be concerned in a patient of this age to rule out any malignancy of the bowel. Altered bowel habit and abdominal pain are shared symptoms of diverticular disease and colorectal carcinoma, both of which often present in elderly people. Furthermore, as this barium enema illustrates, multiple diverticula in the sigmoid colon may make it difficult to interpret whether any concurrent pathology is present. It would be wise to undertake appropriate flexible bowel endoscopy to rule out any malignancy.

Diverticular disease and colorectal carcinoma can coexist as this film readily illustrates with diverticular disease masking fine mucosal detail.