OBSTRUCTION OF G.I.

1. The most common obstruction of the GI is ABDOMINAL ADHESIONS which occur as a result of:

   • pancreatitis, surgery, etc.

   • old time migraine medications which lead to fibrosis in the abdomen.

2. The 2^nd most common GI obstruction is Hernia (it was the former #1 but now is #2)

High Grade vs. Low Grade GI Obstruction

High Grade (early vs. late)

Early

• In a high grade GI obstruction nothing gets past a certain portion of bowel.

• Parasympathetic driven persitalsis (due to stretch receptors) try to drive matter past the point of obstruction

• Multiple spinal levels get involved and as a result overlapping peristaltic waves that can be heard as increase peristaltic sounds (HYPERPERISTALSIS)

• Colicky pain – signifies an “unsatisfied contraction” meaning the neurological system is intact

• The colicky pain gets, bad, worse, worst, then goes way, only to return again and get even worse.

• The patient with a high grade obstruction will be normal for a while until it gets completely compacted up to that point; The individual may have a couple of Bowel movements after it happens b/c there was fecal matter distal to the site of obstruction.

• The obstruction may be palpable

Late

• At this phase of obstruction the area of involvement is very dilated. The muscular wall of the Small intestine is stretched so much that it is not very contractile.

• There is difficulty draining blood which causes obstruction, which then leads to no blood coming in

• No bowel sounds may be present for up to 5 minutes

• NO bowel movements will be present in Late High Grade Obstruction.

• Contrast is a contraindication in viewing a Late High Grade Obstruction as barium is in suspension when the patient drinks it. The patient will absorb the water and the Barium will be left behind forming a cement plug. A water soluble contrast agent is needed for a High Grade Obstruction so that the vascular tree can take it away.

• Upright KUB shows multiple air fluid levels due to the layering of feces

• Normal air fluid levels

• Stomach, cecum, hepatic flexure, splenic flexure will not be visible.

• 3 or more air fluid levels on a KUB is abnormal and is considered an obstruction unless proven otherwise.

KEY QUESTIONS

1. Is the Bowel movement schedule normal?

2. Is there a decrease in fecal bulk volume?

LOW GRADE

• The low grade GI Obstruction is like a toothpaste tube. It is a big tube with a small opening.

• Transient dilation (painful) occurs proximal to the partial obstruction.

• Low grade Obstruction is less severe than high grade obstruction

• The pain of a Low grade occurs a certain time after the meal.

• The pain occurs specifically when the area proximal to the obstruction dilates. The pain dissipates as some matter goes through the little hole, and the pain decreases as the stretch decreases.

• It is safe to perform a contrast study here

Category: Gastroenterology Notes