The paper measured proteins in jejunal succus entericus and found that the fluid part contained about 2.5 times the serum albumin content of the fluid. It also reported that the additional protein in the cellular debris amounted to about 60% of the protein in the fluid part, and explicitly noted that the proteins could be secreted by the glandular epithelium of the small intestine or liberated from desquamated epithelial cells.

This review states: “Including around 1 L of fluid that is ingested…, the **intestinal fluid load averages ∼9 L/day**. The majority of the fluid load derives from **digestive secretions from the salivary glands, stomach, pancreas, and biliary system**, and **the intestine itself also secretes fluid** to maintain appropriate fluidity of the luminal contents…” It emphasizes that one primary function of the intestinal epithelium is to **transport fluid and electrolytes to and from the luminal contents**, with secretory processes driven mainly by ion transport (e.g., Cl⁻ secretion) rather than cell rupture.

“The intestinal epithelium is a single cell layer that forms a selective barrier between the host and the intestinal lumen. It has a **high turnover rate with complete renewal every 4–5 days in humans**. Enterocytes shed from the villus tip into the lumen in a process termed **cell shedding**.” The review emphasizes that shedding is essential for barrier maintenance and is tightly regulated, and describes that **cells are extruded and die at the villus tip**, contributing cellular material to the lumen, but frames this as part of barrier homeostasis rather than as a primary source of intestinal fluid.

The mucosa between the villi is dotted with deep crevices that each lead into a tubular **intestinal gland** (crypt of Lieberkühn), which is formed by cells that line the crevices. These produce **intestinal juice**, a slightly alkaline (pH 7.4 to 7.8) mixture of water and mucus. Each day, about 0.95 to 1.9 liters (1 to 2 quarts) are **secreted** in response to the distention of the small intestine or the irritating effects of chyme on the intestinal mucosa.

This review notes that **“The epithelium turns over every 2–4 days in mice and every 2–5 days in humans”** and that stem cells at the crypt base generate all epithelial cells which then migrate and are **“eventually shed into the lumen at the villus tip.”** It further states that **“The intestinal epithelium’s primary role is the controlled transport of nutrients, water and ions from the intestinal lumen into the body.”** The article discusses fluid absorption/secretion in terms of epithelial transport and crypt–villus functional differences, not as being dominated by fluid released from rupturing cells.

The abstract explains: **“The intestinal epithelium has one of the highest rates of cellular turnover** in a process that is tightly regulated. As the transit-amplifying progenitors of the intestinal epithelium generate **~300 cells per crypt every day**, regulated cell death and **sloughing at the apical surface** keeps the overall cell number in check.” It focuses on modes of epithelial cell death (apoptosis, necroptosis, pyroptosis) and how shedding maintains epithelial homeostasis and barrier integrity; it does not describe the resulting shed cellular contents as the main contributor to luminal fluid.

The article notes that villi are covered with absorptive enterocytes while "crypt cells are generally regarded as **secretory**." It explains that intestinal epithelium "regulates the balance between absorption and **secretion of fluid and electrolytes**" via transporters and channels such as CFTR, emphasizing regulated transcellular and paracellular transport rather than passive release from cell lysis. There is no mention of normal intestinal juice arising predominantly from rupturing or sloughing epithelial cells; instead the focus is on **active secretory processes** of viable crypt cells.

This experimental paper notes that “**Intestinal epithelial cells (IECs) of the mammalian small and large intestine are regenerated continuously** throughout adulthood from stem cells that reside in a region near the base of intestinal crypts.” It continues: “Absorptive enterocytes in particular are **released into the gut lumen after they have migrated to the tip of the villi where cell apoptosis and shedding occur.** The continuous production of new IECs … is thus balanced by the elimination of older cells at the luminal side of the intestine, **resulting in a rapid turnover of IECs**.” The work quantifies turnover and its regulation by microbiota but does not claim that the fluid content of shed IECs constitutes most intestinal juice.

This review describes that “**intestinal epithelial cells are constantly shed from the villus tip into the lumen**” and that “cell shedding is estimated to occur at a rate of around **10^10 cells per day in humans**.” It explains that shedding is usually an organized process involving actin ring constriction and apoptosis, maintaining barrier integrity. The paper discusses consequences such as transient gaps and barrier dysfunction but does **not** characterize the volume of fluid released from shedding as the predominant component of intestinal secretions; instead, it emphasizes the **cellular and barrier aspects** of the process.

NIDDK states: "The muscles of the small intestine mix food with **digestive juices from the pancreas, liver, and intestine**, and push the mixture forward for further digestion." Elsewhere it explains that digestive juices are produced by glands in various organs and mixed with chyme. The discussion characterizes intestinal juice as a **secreted fluid** that mixes with chyme, without describing epithelial cell rupture or sloughing as its main source.

This overview explains that stem cells in the crypt give rise to progenitors that migrate up the villus and are **“shed at the villus tip into the intestinal lumen”**, highlighting the dynamic turnover of the epithelium. It emphasizes that **crypt cells are predominantly secretory** whereas villus cells are absorptive, and that secretory processes in the crypts contribute to fluid movement in the lumen. The article frames cell shedding as a way to remove aged or damaged cells while **fluid transport is described separately as an epithelial transport function**, not as being dominated by the cytoplasmic contents of shed cells.

This review states that “**Intestinal water transport is a passive process driven by osmotic and hydrostatic forces**” generated by active solute transport. It elaborates that “The small intestine receives approximately **8–9 liters of fluid per day**, mainly from oral intake and **secretions from salivary glands, stomach, pancreas, liver, and intestinal mucosa**, and absorbs most of it.” The discussion attributes luminal fluid to these **exocrine and mucosal secretions and ingested water**, and does not describe epithelial cell lysis or sloughing as a major fluid source.

For the small intestine, the site notes: "**Digestive juice produced by the small intestine** combines with pancreatic juice and bile to complete digestion." This phrasing indicates that the small intestine **produces** a digestive juice, aligning with secretion by glands and epithelial cells. The resource does not describe the contents of ruptured or sloughed epithelial cells as the primary source of this fluid.

IFFGD explains that within the GI tract, "The salt and water come from the food and liquid we swallow and the **juices secreted by the many digestive glands**." In describing intestinal function, it emphasizes **secretions from glands** as the source of fluid within the lumen. The overview does not characterize intestinal juice as mostly derived from epithelial cell rupture or sloughing.

In outlining mechanisms of diarrhea, the article explains that “**Fluid secretion in the small intestine results from activation of chloride secretion by crypt enterocytes**,” with sodium and water following passively, and that increased secretion or reduced absorption produces excess luminal fluid. It further notes that diarrhea can occur with **normal epithelial cell turnover**, underscoring that **secretory processes**, not cell rupture, dominate fluid fluxes. The paper does not suggest that the majority of luminal fluid originates from the contents of sloughed epithelial cells.

In lecture notes on intestinal physiology, secretion is described as an active process: intestinal crypt cells "secrete Cl− via CFTR channels; Na+ and water follow paracellularly," producing fluid in the lumen. The notes distinguish **secretion by crypt enterocytes** from absorption by villus enterocytes and do not state that most luminal fluid derives from cell lysis. Cell turnover and sloughing are described elsewhere in physiology texts as part of epithelial renewal, but not as the main source of intestinal juice volume.

KidsHealth describes that in the small intestine, "Digestive juices from the **pancreas, liver, and intestine** help break down food further." The explanation for a lay audience consistently frames these as **juices produced by organs and glands**, not as fluid arising from breakdown of epithelial cells. No mention is made of sloughed epithelial cell contents being a major contributor to intestinal juice.

This classic work (often cited in later reviews) reports that “The loss of epithelial cells from the tips of villi is a visible phenomenon in the opened small intestine of the dog.” It quantifies **rates of epithelial cell loss and replacement** along the villus and crypt, establishing that villus-tip cell loss is continuous. The focus is on **cell number and turnover kinetics**; it does not describe the volume of liquid contributed by these cells nor claim that their lysis accounts for most intestinal juice.

The lecture states that "the main component of **intestinal juices are water" and that intestinal juices are "secreted" by specialized cells in the intestines. It lists electrolytes, enzymes, bicarbonate, and mucus in the juice and describes neural and hormonal regulation of **secretion of intestinal juices**. The talk repeatedly uses the language of glandular/epithelial secretion and does not suggest that most intestinal juice comes from rupturing or sloughing epithelial cells.

Widely used human physiology textbooks (e.g., Guyton & Hall, Boron & Boulpaep) describe **intestinal juice** as a fluid of ~1–2 L/day secreted by the crypts of Lieberkühn in the small intestine, consisting largely of water and electrolytes, with mucus from goblet cells and enzymes from brush border cells. They describe rapid turnover and sloughing of intestinal epithelial cells as part of mucosal renewal, contributing to luminal cellular debris, but not as the primary origin of the fluid volume of intestinal juice. Instead, the main volumetric source of small-intestinal luminal fluid is active secretion by crypt epithelial cells and exocrine glands, plus ingested water and gastric/pancreatic/biliary secretions.

Vedantu states that intestinal juice is secreted in a very small quantity in the small intestine and is produced by the crypts of Lieberkühn. It also says the composition includes water, mucoproteins, hydrogen carbonate ions, and enzymes.

The video says succus entericus has about 99.5% water and 0.5% solids, and that enzymes are produced and released into it by the enterocytes of the villi. It also says intestinal mucosa secretes intestinal hormones that promote secretion by stimulating the intestinal glands.