• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of gutGutCurrent TOCInstructions to authors
Gut. Aug 1988; 29(8): 1035–1041.
PMCID: PMC1433896

Measurement of gastrointestinal pH profiles in normal ambulant human subjects.


Gastrointestinal (GI) pH has been measured in 66 normal subjects using a pH sensitive radiotelemetry capsule passing freely through the gastrointestinal tract. Signals were recorded with a portable solid state receiver and recording system, enabling unconstrained measurements with normal ambulatory activities for up to 48 h during normal GI transit. Capsule position in the gut was monitored by surface location using a directional detector. Gastric pH was highly acidic (range 1.0-2.5) in all subjects. The mean pH in the proximal small intestine was 6.6 (0.5) for the first hour of intestinal recording. By comparison the mean pH in the terminal ileum was 7.5 (0.4) (p less than 0.001). In all subjects there was a sharp fall in pH to a mean of 6.4 (0.4) (p less than 0.001) as the capsule passed into the caecum. Values are means (SD). pH then rose progressively from the right to the left colon with a final mean value of 7.0 (0.7) (p less than 0.001).

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.1M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Reynolds JR, Walt RP, Hardcastle JD, Clark AG, Smart HL, Langman MJ. 24-hour intragastric pH: continuous monitoring or nasogastric aspiration? Digestion. 1986;33(4):219–224. [PubMed]
  • Bown RL, Gibson JA, Sladen GE, Hicks B, Dawson AM. Effects of lactulose and other laxatives on ileal and colonic pH as measured by a radiotelemetry device. Gut. 1974 Dec;15(12):999–1004. [PMC free article] [PubMed]
  • Watson BW, Meldrum SJ, Riddle HC, Brown RL, Sladen GE. pH profile of gut as measured by radiotelemetry capsule. Br Med J. 1972 Apr 8;2(5805):104–106. [PMC free article] [PubMed]
  • Colson RH, Watson BW, Fairclough PD, Walker-Smith JA, Campbell CA, Bellamy D, Hinsull SM. An accurate, long-term, pH-sensitive radio pill for ingestion and implantation. Biotelem Patient Monit. 1981;8(4):213–227. [PubMed]
  • Evans DF. Twenty-four hour ambulatory oesophageal pH monitoring: an update. Br J Surg. 1987 Mar;74(3):157–161. [PubMed]
  • Atkinson M. Monitoring oesophageal pH. Gut. 1987 May;28(5):509–514. [PMC free article] [PubMed]
  • Branicki FJ, Evans DF, Ogilvie AL, Atkinson M, Hardcastle JD. Ambulatory monitoring of oesophageal pH in reflux oesophagitis using a portable radiotelemetry system. Gut. 1982 Nov;23(11):992–998. [PMC free article] [PubMed]
  • Slater EJ, Evans DF, Foster GE, Hardcastle JD. A portable radiotelemetry receiver for ambulatory monitoring. J Biomed Eng. 1982 Jul;4(3):247–251. [PubMed]
  • Jacob R, Riddle H, Watson BW. Circuit for searching for a signal from a three aerial system during inductive loop telemetry. Biomed Eng. 1973 Jul;8(7):292–295. [PubMed]
  • Thornton JR. High colonic pH promotes colorectal cancer. Lancet. 1981 May 16;1(8229):1081–1083. [PubMed]
  • Doll R. The geographical distribution of cancer. Br J Cancer. 1969 Mar;23(1):1–8. [PMC free article] [PubMed]
  • Hill MJ. Bacteria and the etiology of colonic cancer. Cancer. 1974 Sep;34(3):suppl–suppl:818. [PubMed]
  • Narisawa T, Magadia NE, Weisburger JH, Wynder EL. Promoting effect of bile acids on colon carcinogenesis after intrarectal instillation of N-methyl-N'-nitro-N-nitrosoguanidine in rats. J Natl Cancer Inst. 1974 Oct;53(4):1093–1097. [PubMed]
  • Reddy BS, Watanabe K, Weisburger JH, Wynder EL. Promoting effect of bile acids in colon carcinogenesis in germ-free and conventional F344 rats. Cancer Res. 1977 Sep;37(9):3238–3242. [PubMed]
  • Walker AR, Walker BF, Segal I. Faecal pH value and its modification by dietary means in South African black and white schoolchildren. S Afr Med J. 1979 Mar 24;55(13):495–498. [PubMed]
  • Stower MJ, Hardcastle JD. The results of 1115 patients with colorectal cancer treated over an 8-year period in a single hospital. Eur J Surg Oncol. 1985 Jun;11(2):119–123. [PubMed]
  • Gilbert J, Kelleher J, Littlewood JM, Evans DF. Ileal pH in cystic fibrosis. Scand J Gastroenterol Suppl. 1988;143:132–134. [PubMed]

Articles from Gut are provided here courtesy of BMJ Group


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


  • MedGen
    Related information in MedGen
  • PubMed
    PubMed citations for these articles

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...