The high energy nutritional supplement Resource® Energy is approved for human nutritional support in various clinical conditions, yet it has been used off-label to alleviate the effects of hunger during bowel preparation for colonoscopy. Its impact in mucosa visualization quality and hunger alleviation is unknown. The product is liquid and nutritious but it is not transparent, thus it is conceivable that it could alleviate the discomfort of hunger during the preparation but possibly compromising mucosa visualization. In this study, participants who will undergo a colonoscopy (requested for an explicit medical indication) will take two bottles of the nutritional supplement during the usual bowel preparation. The quality of mucosal visualization and the participants opinion regarding satiety and product tolerance during bowel preparation will then be analysed.

The high energy nutritional supplement Resource® Energy is approved for human nutritional support in various clinical conditions. However, it has been recommended by pharmacists to reduce hunger during bowel preparation for colonoscopy, without any medical prescription or recommendation as there is no scientific evidence regarding this use. Its impact in the quality of mucosal visualization during colonoscopy and in relieving hunger is unknown, thus requiring research.

The dietary supplement is liquid and nutritious, each serving consisting of 200 mL containing carbohydrates 42 g, lipids 10 g, proteins 11.2 g and fiber < 1 g, totalling 303 kcal. It is thus conceivable that it can mitigate the discomfortable feeling of hunger during bowel preparation, but because it is not transparent it could possibly hamper mucosa visualization.

One hundred and fifty control patients (with clinical indication for undergoing colonoscopy) will undergo bowel preparation as usual with the standard of care polyethylene glycol 3350 in 4 litres of water (Klean-Prep®): one day before the colonoscopy with no ingestion of solid foods, possibly with ingestion of clear liquids with or without sugar (such as tea or other transparent beverages without pulp, but not milk, yogurt, broth or gelatine), and with ingestion of 275,84 g (4 sachets) of polyethylene glycol 3350 in 4 litres of water in 3 to 4 hours (250 mL every 15 minutes), starting at 18:00; in the day of the exam the patients can drink the same clear liquids with or without sugar until 4 hours before the colonoscopy, which will be carried out in the morning.

One hundred and fifty patients (with clinical indication for undergoing colonoscopy) will undergo bowel preparation as usual and take two servings of Resource® Energy Apricot.

All patients will be asked about feelings of hunger or side effects of bowel preparation and colonoscopy (nausea, vomits, abdominal pain, abdominal discomfort, abdominal pressure, abdominal bloating, syncope, blood in stool, sleep disturbance, work absenteeism) in a scale from 0 to 10, before and after the colonoscopy. This scale is often used to assess appetite.

Colonoscopic mucosa visualization quality will be assessed in all patients using the Boston Bowel Preparation Scale, which is the most thoroughly validated and recommended scale.

Statistical comparison will the be performed between both groups, regarding colonoscopic mucosa visualization and side effects and sensations experienced, such as hunger.

Inclusion Criteria:

• individual requesting a non-contraindicated colonoscopy (with clinical indication) at the outpatient clinic.

Exclusion Criteria:

• pregnancy
• Allergy to any ingredient of Resource® Energy Apricot