This is a single-blind randomized controlled trial with a stratified (diabetes mellitus, non-diabetes mellitus), balanced randomization (1:1), placebo-controlled study regarding the effect of carbohydrate loading 2 hours prior to the outpatient upper endoscopic procedure. All patients who were assigned for outpatient oesophagogastroduodenoscopy (OGDS) were invited to join in this study voluntarily from January 2021 until August 2021. This study was conducted in the Endoscopy Unit, Hospital Universiti Sains Malaysia, Kubang Kerian, Malaysia. The endoscopists that performed this procedure were blinded and there was trained staff who was not involved in the study to assess the well-being score. The study protocol had been approved by the Human Research Ethics Committee of Universiti Sains Malaysia (JEPeM) with the assigned protocol code USM/JEPeM/20080414.

Patient planned for OGDS in HUSM will be randomized into 2 groups. Plain water is given to group A of subject and carbohydrate loading is given to group B subject 2 hours before OGDS. Gastric residual volume is visualized directly and measured through aspiration via OGDS and subject's well-being is assessed for both group of the subject prior and after clear fluid have been given.

Methodology :

Research design :- This is a single-blind randomized controlled trial. This is a stratified (diabetes mellitus, non-diabetes mellitus) with balanced randomization (1:1), placebo-controlled study Study area :- This study will be conducted in the endoscopy room, Hospital Universiti Sains Malaysia (HUSM) in Kubang Kerian, Kelantan, Malaysia

All subjected planned for OGDS with the complaint of one or more of the following symptoms : Bothersome postprandial fullness, early satiety, epigastric pain or epigastric burning and fulfill the inclusion criteria are selected. Patients will be approached and be explained regarding the study in surgical outpatient clinic before OGDS. The patient will be approached again on the day of OGDS, if agree to participate, informed consent will be obtained. Informed consent will be obtained after explanation regarding the study and procedure again by researcher nurse.

The allocation sequence is according to computer-generated random number list, it was prepared by an investigator with no clinical involvement in the trial. The allocation sequence was concealed from researcher enrolling and assessing participants. The allocation sequence will be sealed in sequentially numbered and opaque envelopes. A manila card will be placed inside envelop to render it impermeable to intense light. To prevent subversion of the allocation sequence, the name and identification number of the participants will be written on a book together with the series number on the envelope. The details in the book will be kept confidentially.

After enrolled subject complete all the baseline assessment, the corresponding envelope will be enclosed by the trained staff (who not involved in the study) who prepare the drink. The staff need to ensure that the envelop is still sealed when receiving it. The staff will prepare the drink into an identical container according to the assignment.

The subjects are randomized into 2 groups: 1 group with 400mL plain water and another group given 1 packet carborie (400mL). Subjects need to finish the drink over 10 minutes. After that, subjects are not allowed to leave endoscope room until finish OGDS to prevent consumption of other drink or food.

2 hours after that, the subject undergoes OGDS. OGDS is performed following the standard protocol.

1. The patient lies in the left lateral position
2. Medication/lignocaine spray to numb the back of throats (spray) will be given to prevent gagging during the passage of the instrument
3. A plastic mouth guard (mouthpiece) is placed between the teeth to prevent damage to the teeth and endoscope
4. The endoscope (also called a gastroscope) will be inserted through the mouthpiece
5. A small container or yankauer suction is placed close to the mouth of a patient to collect saliva during and after the oesophagogastroduodenoscopy (OGDS)
6. The endoscope will be inserted along the middle line of the soft palate
7. Once endoscope advanced, the patient may be asked to swallow to facilitate advancement of scope
8. Throughout the procedure, no water flushing is allowed, only air inflation is allowed.

Visualized pooling of fluid in the stomach is aspirated until dry via direct visualization with the endoscope. The aspirated fluid will be collected in the suction reservoir and the fluid will be measured

Subject's well-being score is assessed via visual analogue scale (VAS) which consist of 5 parameters: hunger, thirst, anxiety, tiredness and general discomfort. This scale will be used repeatedly during this study to assess the patient's well-being. The trained staff nurse will ask the patient regarding the level of 5 parameters and subject need to mark [X] somewhere along the horizontal line given before drink and before OGDS procedure.

All subjects are advised to inform assessor if there is an adverse reaction. Medical personnel are available to manage any adverse events that might occur throughout the procedure.

The possible risk that may arise in the study includes injury to the gastrointestinal wall, aspiration and bleeding which is the similar risk for all patient undergoing for OGDS procedure. The small volume of the drink will not cause psychological distress to the subject, but its taste may not be palatable.

Inclusion Criteria:

• Patient 18 years old and above
• Agree to participate

Exclusion Criteria:

• History of upper gastrointestinal surgery
• Patient with active gastrointestinal bleeding
• Unstable clinical condition
• Mentally disable or who cannot give an informed consent
• Patient on the nasogastric feeding tube
• Pregnant patient
• American Society of Anesthesiologists classification of physical status grade 3 or above
• Insulin dependent Diabetes Mellitus more than 10 years
• Patient who is carbohydrate intolerance