This cross-sectional study aims to determine the prevalence of lactose intolerance among patients with chronic diarrhea, assess its correlation with age and gender, and evaluate common symptoms in affected patients. The study will collect demographic data, conduct lactose intolerance testing via PCR, and use a symptom questionnaire.

The study is designed as a cross-sectional analysis conducted at a single healthcare center. Its primary objectives are:

To determine the point prevalence of lactose intolerance in patients suffering from chronic diarrhea (lasting more than four weeks).

To explore potential correlations between lactose intolerance and demographic factors such as age and gender.

To identify the most common symptoms associated with lactose intolerance in this patient population.

Methodology:

Data Collection: Demographic information (age, sex, medical history, and diarrhea duration) will be gathered.

Lactose Intolerance Testing: Polymerase Chain Reaction (PCR) will be employed to diagnose lactose intolerance.

Symptom Questionnaire: A standardized questionnaire will be administered to document symptoms like abdominal pain, bloating, flatulence, diarrhea, and nausea.

Inclusion Criteria:

• All Patients with IBS diarrhea dominant type meet Rome criteria attending at Al-Rajhy University Hospital during 6 months (from march to September). A patient must have recurrent abdominal pain (at least 1 day per week in the last 3 months) associated with at least two of the following:

  1. Related to defecation (pain improves or worsens with bowel movements).
  2. Change in stool frequency (diarrhea or constipation).
  3. Change in stool form (appearance) (loose, watery, hard, or lumpy).

• Patients aged >18 years.

• Both males and females

Exclusion Criteria:

• -patient aged<18 years old.
• Patients with chronic diarrhea don't meet Rome criteria
• patients with malignancies

The study population consists of adult patients aged 18-70 years diagnosed with chronic diarrhea lasting more than four weeks. Both male and female participants are included. Participants will be recruited from a single healthcare center. They will undergo comprehensive assessments, including demographic profiling, medical history review, and diagnostic testing for lactose intolerance using PCR. The diversity in age and gender ensures that potential correlations with these variables can be analyzed.