Colonic obstruction

Question 1

Cancer

Answer 1

Usually insidious onset
History of progressive constipation
Systemic features (e.g. anaemia)
Abdominal distension
Absence of bowel gas distal to site of obstruction

Establish diagnosis (e.g. contrast enema/ endoscopy)
Laparotomy and resection, stenting, defunctioning colostomy or bypass

Question 2

Diverticular stricture

Answer 2

Usually history of previous acute diverticulitis
Long history of altered bowel habit
Evidence of diverticulosis on imaging or endoscopy

Once diagnosis established, usually surgical resection
Colonic stenting should not be performed for benign disease

Question 3

Volvulus

Answer 3

Twisting of bowel around its mesentery
Sigmoid colon affected in 76% cases
Patients usually present with abdominal pain, bloating and constipation
Examination usually shows asymmetrical distension
Plain X-rays usually show massively dilated sigmoid colon, loss of haustra and U shape are typical, the loop may contain fluid levels

Initial treatment is to untwist the loop, a flexible sigmoidoscopy may be needed
Those with clinical evidence of ischaemia should undergo surgery
Patient with recurrent volvulus should undergo resection

Question 4

Acute colonic pseudo-obstruction

Answer 4

Symptoms and signs of large bowel obstruction with no lesion
Usually associated with metabolic disorders
Usually a cut off in the left colon (82% cases)
Although abdomen tense and distended, it is usually not painful
All patients should undergo contrast enema (may be therapeutic)

Colonoscopic decompression
Correct metabolic disorders
IV neostigmine
Surgery