- Post operative adhesions
-
The most common cause of small bowel obstruction seen in adults in
hospital. [MPM+87,TW95] Many will settle on
conservative management and do not need further surgery. Most
clinicians advocate a drip and suck policy for several days if there is
no evidence of a complication. More recently some have advocated a
therapeutic triail of 100 ml of Gastrografin by mouth to
differentiate partial from complete obstruction. [BDJ+03]
- Stuck onto a tumor or inflammatory mass somewhere
-
It is not unusual to encounter a patient with obstruction due to a
normal part of bowel becoming stuck onto a tumor or other inflammatory
mass. It may be necessary to resect the main pathology en bloc with the
adherent loops of bowel and then do multiple reconstructions.
- Hernia; External or Internal
-
External hernia are common, internal herniae are rare. A common
clinical situation is an elderly lady who is admitted with small bowel
obstruction. The presence of a femoral hernia
as the cause of
the ladies problem is often missed by several of the first doctors to
examine the patient. Remember to specifically check for evidence of herniation
through the hernial orifices in patients with intestinal obstruction.
Especially remember to check for the presence of femoral herniae in
elderly ladies who present with intestinal obstruction. It is usually
recommended that femoral herniae are repaired even if they are
asymptomatic because they have a greater chance of causing problems
than inguinal herniae.
- Volvulus
-
Volvulus is twisting of the bowel.
Small intesintal
volvulus is seldom diagnosed pre-operatively. There is a high rate of
necrosis of the bowel when it is discovered. Suspicion should be high
when the patient has severe pain and there is any evidence of
peritonitis. If the bowel is obviously dead, it is not wise to release
the volvulus as this may aggravate the patients illness by release of
inflammatory mediators and toxins into the general circulation.
However, if the bowel is dubious it is best to release the volvulus,
untwist it and place the bowel in warm packs for a period to see if
there is improvement. If there is no improvement resection is best. If
there is some improvement but the bowel still appears somewhat dubious,
it may be possible to do a second look laparotomy after 24 hours and
then do resection if necessary.
- Intussusception
-
As mentioned above, this is mainly a problem encountered by paediatric
surgeons.
- Benign Strictures
-
The commonest benign stricture of the small intestine is due to Crohn's
disease. It may be difficult to be sure if the stricture is due to
inflammation with oedema or is a fibrotic stricture. Surgery may be
delayed until medical therapy has been maximised. Infliximab (anti
tumor necrosis factor alpha) may increase fibrosis. The surgeon may
have to perform an enterotomy and pass a Foley catheter up and down the
bowel to identify all the strictured areas. The balloon is inflated
with 2.5 ml of saline and any areas of hold up represent strictures, it
is best to treat these by stricturoplasty rather than resection, to
preserve intestinal length and avoid the short bowel syndrome.
Other causes of benign stricture of the small bowel, include ischaemia,
and healing from injury, for instance due to radiation, a foreign body,
recurrent impaction in a hernial orifice and post anastomotic.
- Tumors of the small intestine
-
Small intestinal tumors are much rarer than colonic tumors. They may be
benign (leiomyoma, stromal) or malignant (lymphoma, carcinoid,
adenocarcinoma). If polypoid (Peutz Jaegers) they may present by
Intussusception.
