Fluid loads along the GI tract:
Each day, close to 10 L of fluid composed of ingested food & drink & secretions from the salivary glands, esophagus, stomach, pancreas, bile duct, & duodenum pass the ligament of Treitz.
The 𝗷𝗲𝗷𝘂𝗻𝘂𝗺 absorbs approximately 6 L & the 𝗶𝗹𝗲𝘂𝗺 2.5 L, leaving about 1.5 L to pass into the colon each day.
The 𝗰𝗼𝗹𝗼𝗻 absorbs more than 90% of this load, leaving about 0.1 L in feces.
The overall efficiency of water absorption is 99%, & a reduction of this efficiency by as little as 1% may lead to 𝗱𝗶𝗮𝗿𝗿𝗵𝗲𝗮.