Rectal potential difference and histology in Crohn's disease

Area of Science:

• Gastroenterology
• Physiology

Background:

• Crohn's disease (CD) is a chronic inflammatory bowel disease.
• Rectal potential difference (PD) reflects ion transport across the rectal mucosa.
• Assessing rectal PD may offer insights into CD pathophysiology.

Purpose of the Study:

• To establish a normal range for rectal PD in healthy individuals.
• To investigate the relationship between rectal PD and disease activity in Crohn's disease.
• To evaluate the utility of mineralocorticoid stimulation in assessing rectal function in CD.

Main Methods:

• Measured resting rectal PD in 27 CD patients and 16 controls.
• Performed sigmoidoscopy and rectal biopsy in CD patients.
• Administered oral fludrocortisone to 13 CD patients to assess PD response.

Main Results:

• Mean resting rectal PD was significantly lower in active CD and with superficial epithelial abnormalities.
• Patients with diarrhea had lower mean resting PD compared to those with normal bowel habits.
• Rectal PD failed to increase with fludrocortisone in patients with active disease.

Conclusions:

• Reduced rectal PD in active CD suggests impaired rectal sodium transport may contribute to diarrhea.
• Mineralocorticoid stimulation is less sensitive than sigmoidoscopy or biopsy for detecting minor mucosal abnormalities in CD.