Colonoscopy is a commonly used minimally invasive method for evaluating the lower gastrointestinal tract. The quality of colonoscopy is assessed by factors such as cecal intubation rate and adenoma detection rate, both of which are affected by bowel preparation. Adequate bowel cleansing is critical for an ideal colonoscopy. Inadequate bowel preparation can prolong the procedure time, miss pathological findings, and increase hospital costs due to repeated procedures. Studies have shown that nearly 25% of patients have inadequate bowel preparation. Several factors influence bowel cleansing, including diet, bowel preparation medication, and a history of gastrointestinal surgery. In a study, male gender, hospitalization, and spring season were reported as independent risk factors for inadequate bowel preparation. A retrospective US study associated age ≥66 with poor colonoscopy preparation, while two Asian studies associated age ≥60. Comorbidities such as diabetes, stroke, and dementia, as well as low socioeconomic status, have also been reported to negatively impact adequate bowel cleansing.

The Aronchick scale, Ottawa Bowel Preparation Scale (OBPS), and Boston Bowel Preparation Scale (BBPS) are commonly used in bowel preparation scoring. The BBPS is rated from 0 to 9, with 9 considered excellent bowel preparation. It is applied after cleansing and aspiration of colon segments, which are divided into right, transverse, and left colon. Among the current scoring systems, the BBPS is the most useful and reliable scale.

The positive effects of alkaline pH water on the gastrointestinal system are well known. Alkaline mineral water has positive effects on intestinal epithelial regeneration, inflammatory response, improved barrier function, and antioxidant mechanisms.

In this study, researchers aimed to investigate the effect of the pH value of water consumed during bowel preparation before colonoscopy on bowel cleansing.

Demographic, clinical, and intraoperative data of patients undergoing colonoscopy in investigators hospital's surgical endoscopy unit between July 2026 - July 2027 will be examined. Patients meeting the inclusion criteria will be included in the study. For pre-procedure information, all patients will be given a bowel preparation form by the surgical endoscopy unit, and patients who do not fully adhere to the diet will be excluded from the study. Informed consent will be obtained from the patients or their legal representatives. All procedures will be performed under sedation with the assistance of an anesthesiologist. Bowel cleansing will be assessed according to the Boston Bowel Preparation Scale (BBHS). The pH value and content of the drinking water will be noted when the bowel preparation form is given; no specific instructions will be given regarding this. However, patients will be asked to use the same water throughout the bowel preparation period. Data regarding drinking water will be confirmed on the day of the procedure for a second check.

This study will be the first of its kind in this field.

Inclusion Criteria::

• Age over 18
• Fully adhering to the pre-procedure diet
• Bowel preparation performed with the bowel preparation routinely used in our surgical endoscopy unit (Sennoside A+B, Monobasic sodium phosphate+ Dibasic sodium phosphate)
• No history of gastrointestinal surgery
• Patients not using prokinetic drugs

Exclusion Criteria:

• Those not following the diet
• Those using another bowel preparation
• Those with a history of stomach, small intestine, large intestine surgery or any major abdominal surgery for any reason
• Those diagnosed with a known bowel disease such as inflammatory bowel disease or irritable bowel syndrome
• Those with gastrointestinal motility disorders or those using medications that may cause this side effect
• Patients for whom the pH value/content of drinking water cannot be obtained

Demographic, clinical, and intraoperative data of patients undergoing colonoscopy in our hospital's surgical endoscopy unit between July 2026 - July 2027 will be examined. Patients meeting the inclusion criteria will be included in the study. For pre-procedure information, all patients will be given a bowel preparation form by the surgical endoscopy unit, and patients who do not fully adhere to the diet will be excluded from the study. Informed consent will be obtained from the patients or their legal representatives. All procedures will be performed under sedation with the assistance of an anesthesiologist. Bowel cleansing will be assessed according to the Boston Bowel Preparation Scale (BBHS). The pH value and content of the drinking water will be noted when the bowel preparation form is given; no specific instructions will be given regarding this. However, patients will be asked to use the same water throughout the bowel preparation period.