Gastric Lavage or Stomach Wash

by | Apr 21, 2024 | Nurse Article | 0 comments

Stomach wash or gastric lavage means to wash out or irrigate the stomach with a solution. It is used most frequently as an emergency treatment in gastric dilatation and poisoning.


1.  To remove the ingested poisons or any irritati​ng matter from the stomach.

2.  To relieve nausea and vomiting in case of acute dilatation of stomach, pyloric stenosis and intestinal obstruction.

3. To cleanse the stomach as a preparation for surgery.

4. To obtain casts of epithelial cells for bacteriological studies.

Principle involved in the Gastric Lavage:

The gastric lavage is usually accomplished by means of siphon. A siphon is a device used for drawing a liquid from one vessel into another or from a higher level to a lower level, provided the surface of the liquid is exposed to the atmosphere. The siphon operates because of the variation in the atmospheric pressure on the liquid at different levels.

The siphon is a simple apparatus consisting of a bent tube having a short arm and a long arm. The short arm of the siphon is placed in the liquid to be emptied and the long arm is carried down to the lower level. The air must be first removed from the siphon tube before it operates. When air is removed, fluid flows because of the different pressure in the two arms. Pressure in the short arm of the siphon tube is the resultant of atmospheric pressure pressing up in the tube and the pressure due to the column of liquid in the shorter arm pressing down in the tube.

Likewise, the pressure in the long arm is the resultant of atmospheric pressure pressing up in the tube and the pressure due to the column of liquid pressing down in the tube. Since the depth of the column of liquid is greater in the long arm, the resultant pressure here is less than the pressure in the short arm and the fluid will flow from the shorter arm to the longer arm until the air enters the system and produces equilibrium once again.

In gastric lavage, the gastric tube acts as a siphon tube. The part of the tube that goes into the stomach acts as the short arm  and the part of the tube that lies outside the body acts as the long arm of the siphon. The end of the tube that goes into the stomach lies under the level of the fluid in the stomach and the other end of the tube goes below the level of the stomach. When the air is expelled from the tube, the contents of the stomach will drain out.

Solutions Used:

1. Plain water (Plain water is particularly useful when the poison is unidentified)

2. Normal saline

3.Weak solution of sodium bicarbonate or boric acid in corrosive poisoning

4. Specific antidotes: if the person is identified. There are three types of antidotes.

a. Physical antidotes: it is the one that mixes with the poison and dilutes the poison or prevents its absorption or soothes and protects the mucus membrane.

b. Chemical antidotes: These react with the poison and neutralize it.

c. Physiologic antidotes: these have a systemic effect opposite to that of the poison. If the poison has depressive action, the antidote has stimulating effect on the body.

Amount of Fluid:

Gastric lavage is carried until the return flow is clear. About 500 ml of fluid is to be introduced at a time to reach all parts of the mucus membranes of the stomach.

General Instructions:

1. Explain the procedure to the patient (if the patient is conscious) to win his confidence and co-operation. Remove dentures. Introduce a mouth gag in case of an unco-operative patient to prevent him biting the tube.

2. Ask the help of a doctor to insert the gastric tube in patients with depression of the central nervous system. Be ready to introduce an endotracheal tube with cuff to prevent aspiration of vomitus into the respiratory passages.

3. Insert the tube slowly and gently to prevent trauma to the tissues. Lubricate the tube with a water soluble jelly to make the insertion easy and to prevent friction.

4. Be prepared to suck the airway immediately, in case the patient vomits during the insertion of the tube. If vomiting takes place, immediately turn the patient to a three quarter prone position to prevent aspiration of fluid into the lungs.

5. Ensure proper placement of the tube (in the stomach). The stomach contents can be aspirated only if the tube is placed in the stomach.

6. Secure the tube with adhesive tapes to prevent displacements of the tube.
When the tube is in, aspirate the gastric contents completely and save it for laboratory analysis. Label them properly and send it to the lab.

7. Introduce about 500 ml of fluid (irrigating solution) into the stomach and observe the patient’s response to the inflow. Stop inflow, if any signs of intolerance occur such as retching, vomiting, coughing, tachycardia etc.

8. Avoid introducing air into the stomach.

9. When the fluid is introduced into the stomach, invert the funnel and bring the distal end of the tube below the level of the stomach  to drain the fluid from the stomach.

Note the quantity of input and output. If the outflow of fluid is reduced significantly, it is necessary to correct the position of the tube. Save all fluid returned from the stomach for laboratory analysis. Record the total fluid volume instilled and the total volume returned. If there is any discrepancies, notify to the physician.

10. If any blood appears in the outflow, stop the procedure and inform the doctor.
During the procedure, observe the patient’s vital signs, degree of consciousness etc., every 15 minutes. If the condition is deteriorating, stop the irrigation.

11. Continue the treatment till the return flow is clear, or the desired effect is obtained.

12. To discontinue the lavage, pinch off or clamp the tube and withdraw it quickly.

13. The patients may appreciate the use of some pleasant flavored mouth washes after the tube is removed.

14. If it necessitates the removal of undigested food particles or quick removal of poisonous substances, it will be necessary to introduce a gastric tube with a large lumen (e.g. Ewald’s tube) passed via mouth into the stomach. If the tube has to be retained after the stomach  wash a nasogastric tube may be passed instead of Ewald’s tube.


 The tube is introduced either orally or through the nose.

1. Wash hands.

To prevent cross infection.

2. Take the tube and check whether it is in good order. Expel the water from the tube and check the tube for patency.

Any blockage should be corrected before introducing the tube. If any water is remaining in the tube, it can dribble into the trachea and choke the client.

3. Measure distance on the tube from the bridge of the nose to the ear lobe plus the distance from the ear lobe to the tip of the xiploid process of the sternum. Mark the distance of the tube.

Rough guide to determine approximate length of the tube to reach the stomach.

4. Lubricate the tube for about 6 to 8 inches with the lubricant, using a rag piece or a paper square. Lubricant should be applied to the minimum.

Lubrication of the tube reduces friction between mucus membrane and the tube. If the lubricant is excessive, it may dribble into the trachea during the intubation and cause respiratory distress.

Hold the tube coiled in the right hand and introduce the up into the left nostril.

Nasal septum is deviated into the right side.

5. Pass the tube gently but quickly backwards and downwards. Momentary resistance may occur as the tube is passed into the naspharynx. Have the client to flex the head. Withdraw the tube about one inch, rotate it side to side and gently advance the tube.

Flexing of the head helps to flex the tube at the naso-pharyngeal junction and the tube enters the pharynx. Stop if there is marked resistance and inspect the posterior  cavity for coiled tubing.

6. When the tube reaches the pharynx the client may gag. Allow him to rest for a moment. Ask him to take panting breaths.

Panting relaxes the pharynx. A brief pause may prevent vomiting.

7. Have the client take sips of water and swallow on command. Advance the tube 3 to 4 inches each time client swallows. Continue to advance the tube until it reaches the previously designated mark.


Swallowing facilitates the swallowing of the tube through the oesophagus. Mark on the tube indicates the tube has reached the stomach.

After making sure that the tube is in the stomach, aspirate the contents first and save it for laboratory examinations, in case of poisoning, attach a funnel to the tube and fill it with the irrigating fluid. Expel out air from the tube and raise the funnel to allow the fluid to run into the stomach. When 2 or 3 funnels of fluid have run into the stomach, and before the funnel is completely empty, pinch the tube and invert the funnel over a receptacle and allow the fluid to siphon back. Continue the treatment by alternatively introducing fluid into the stomach and permitting it to run back until the return flow is clear or until the desired effect is achieved.

To discontinue the treatment, pinch the tube and pull it quickly. Give a mouth wash and dry the face. Make the patient comfortable. Record the treatment with time and date, on the nurse’s record. Record the type and amount of solution used, the character of return flow, the condition of the patient before, during and after the procedure.