The human microbiota forms a highly complex ecosystem with its host, consisting of hundreds of different species of microorganisms, the majority of which have not yet been cultured. With the recent advent of small subunit rRNA (SSU rRNA) gene sequencing technology, it is estimated that the number of specific gastrointestinal tract phylotypes is more than 1800. Sampling techniques might constitute a major confounder in the read-out of highly sensitive techniques such as SSU-DNA analysis.

It is not properly established whether there is a difference in distribution of luminal bacteria or mucosa adherent bacteria proximal or distal in the colon. In addition, 'bowel lavage' before endoscopy might result in a disturbance of the microbiota in the bowel. For this proof of concept study a novel device capable of taking 'protected' biopsies has been designed.

We hypothesize that the distribution of mucosal and luminal microbiota changes from proximal to distal in the colon, and by taking 'protected biopsies' there will be the opportunity to show the real distribution of microbiota according to the localisation in the colon.

Furthermore, we hypothesize that microbial diversity will differ after bowel lavage.

We hypothesize that the distribution of mucosal and luminal microbiota changes from proximal to distal in the colon, and by taking 'protected biopsies' there will be the opportunity to show the real distribution of microbiota according to the localisation in the colon.

• Inclusion Criteria:

  • Ill prepared colon during index colonoscopy or sigmoidoscopy: Boston scale <3

• Sufficient indication to perform colonoscopy again

Exclusion Criteria:

• Inability to give informed consent

• Life expectancy < 12 months

• Use of combination of two platelet aggregation inhibitors

• Mandatory use of anti-coagulatory medication

• Known history of hemostatic disorder

• Use of systemic antibiotics in preceding 6 weeks

• Use of probiotic or prebiotic treatment in preceding 6 weeks

• Positive stool cultures for common enteric pathogens (Salmonella, Shigella, Yersinia, Campylobacter, enteropathogenic e coli)

• History of surgery:

  • Resection of any part of the colon or Ileocoecal resection
  • Presence of an ileo- or colostoma

outpatients scheduled for colonoscopy for diagnostical purposes who are not known with infectious enterocolitis.