Average diameter & length of small & large intestine

Range small intestine diameter 2.5cm length 291cm: large intestine diameter 4.8cm length 190cm cm Human Homo sapiens Helander HF, Fändriks L. Surface area of the digestive tract - revisited. Scand J Gastroenterol. 2014 Jun49(6):681-9. doi: 10.3109/00365521.2014.898326. p.685 right columnPubMed ID24694282 "When calculating the enlargement of the small intestinal area due to villi, [researchers] averaged the diameter of this part of the intestine to 2.5 cm. The surface enlargements due to villi and microvilli in the small intestine were averaged to 6.5 and 13 times, respectively. It follows that the calculated area of the small intestine will be ASi [Area Small intestine]=291×2.5×p×1.57×6.5×13×10^-4=30m^2. For the large intestine, [researchers] calculated the macroscopic surface area from data published by Khashab et al. [ref 25]. [They] averaged the length to 190cm and the diameter to 4.8cm. The surface enlargement due to microvilli was averaged to 6.5 times. Thus, ALi [Area Large intestine]=190×4.8×p×1×1×6.5×10^-4=1.9m^2. It follows that the total surface area in vivo of the human digestive tract, including the relatively small surfaces of oral cavity (197cm^2), the esophagus (235cm^2), and the stomach (500cm^2), was ~32m^2 (Figure 5)." See BNID 111124 Uri M 111127