• Note that straining to urinate could be confused with straining at stool. A cat who is unable to urinate is experiencing a medical emergency and must be seen by a vet immediately.

• The best treatment for a constipated cat is a human who understands how things work.

• This information is not a substitute for proper veterinary diagnosis and treatment.

The First Lesson

• The inside of the tube called the digestive tract is not inside the body.

• For the eater, the gut wall is the first line of defense between the outside world and the inside of the body.

• Swallowing food gets food into the digestive tract, into the gut, not into the body. Before food can be put to use in the body, it needs to be digested and then absorbed into the body.

Gut 101

• The digestive tract starts at the mouth and ends at the anus with the esophagus, the stomach, the small intestine, and the large intestine in between, all hooked together in a long, continuous, complex tube.

• The digestive system includes organs that actually are inside the body but work closely with the digestive tract – the liver, the gall bladder and the pancreas.

• The digestive tract is self-lubricating.

• The gut wall is composed of smooth muscle cells whose action is involuntary.

• The enteric nervous system is a huge affair; its cells make up a majority of the peripheral nervous system!

• Food provides the nourishment needed by the body to fuel, build, repair and maintain itself and all its parts.

• Before food can nourish, it must be digested so it can be absorbed into the body.

• Food that does not remain in the mouth is not available to ferment in the mouth.

• Many people are surprised by the length of the esophagus.

• For cats, all solid medications and supplements should be 'chased' with sufficient food or water to ensure they make the long journey successfully and do not become entrapped in the esophagus. Chasing liquid medications is also a nice courtesy to avoid potential irritation of the tender mucosa.

• Enzymes break down larger molecules into smaller and smaller molecules.

Gut 102

• The small intestine is a creatively ruffled affair.

• The mesentery is an elegant evolutionary development, a membrane that not only anchors the small intestine yet still allows flexibility of the organ plus provides pick-up-and-delivery service for all those nutrients that are being released from the food.

• Immediately after the chyme arrives in the duodenum, the acid from the stomach is neutralized by a buffer.

• Enzymes from the pancreas are delivered to the duodenum to digest carbohydrates, fats, and to complete the digestion of protein.

• Bile, synthesized by the liver and stored in the gall bladder, enters into the duodenum via the bile duct to emulsify edible fats present in the chyme, resulting in a milky mix called chyle.

• The neutralized chyme flows through the small intestine like a slow swirling river, propelled along by both peristalsis and segmentation.

• As the chyme swirls and flows through the jejunum, molecules of digested nutrients contact the villi and are absorbed via the mesentery into the blood system for distribution to all parts of the body where they are put to use.

• Digestion breaks bigger pieces into smaller and smaller pieces. Mechanical digestion uses physical means to break big pieces down, for greater surface area and better enzymatic access. Chemical digestion employs enzymes to snip the small pieces into smaller molecules by breaking chemical bonds that hold compounds together.

• On and between these folds are millions of tightly packed little fingerlike projections called villi.

• Not only do the villi and their microvilli expand the inner surface area of the small intestine, they also serve as loading docks and gateways.

• There may be 6,000 to 25,000 villi per square inch of intestinal wall, depending on the species whose intestine it is and the particular section of the intestine.

• Just as the theme in digestion is to break big bits into smaller and smaller bits, a circulatory system has a similar theme, working from big through little, littler and littlest, down to the microcirculation level, and circulating back up through small to big again.

• A circulatory system functions as a pick-up-and-delivery system; the system can pick up, transport, and deliver useful and necessary goods or pick up, transport, and dump the waste.

• The smallest blood vessels are not built to withstand the initial pressure of a heartbeat sending blood coursing through the arteries so blood pressure in the little capillaries is much less than blood pressure in the major arteries.

• Capillaries are the key to absorption of nutrients into the circulatory systems.

• Goblet cells emit mucin which in contact with water forms mucous.

• Nutrients are absorbed from the fluid environment of the lumen into the internal fluid environment of the villi where they are picked up by the villi's blood or lymph capillaries and thus into their respective circulatory systems.

• Absorption is not a single process but different strategies depending on what is to be absorbed. There are several possibilities or a combination of strategies.

• Leukocyktes are white blood cells and the villi are well stocked, especially with phagocytes like neutrophils and monocytes who attack potential invaders and gobble up debris.

• Communication between the ENS and the gut occurs across the lining of the gut without the ENS physically entering the lumen.

• The health of the cat depends on the health of the villi who themselves depend on good nutrition and nonexposure to toxic substances. Villi also require the physical passage of food in a use-it-or-start-to-lose-it response.

• The small intestine evolved to transport liquidy contents, not solid objects . . . such as formed hairballs.

• The large bowel makes poop out of soup!

• The large intestine or bowel is also where fermentable dietary fiber in the chyme is fermented by the trillions of gut bacteria who live in the bowel.

• Pressure from the poop, moving into the rectum and pressing from the inside out on the nervous system of the bowel, the enteric nervous system, signals the bowel when it is time to move.


• The problem of constipation is not necessarily lack of water in the

cat, it is lack of water retention in the stool.

Gut Bacteria and Fiber

• Food feeds the cat. Fiber feeds the gut bacteria. And the gut bacteria play an important role in helping to prevent constipation as well as maintaining the health and integrity of the gut wall.

Bacteria 'digest' or ferment the dietary fiber they can make use of, using enzymes just as we do to split large molecules into smaller molecules, and in this process they produce short-chain fatty acids (SCFAs) which provide various benefits to the host (the cat).

SCFAs also help stimulate the necessary smooth muscle contraction in the bowel. Without muscle contraction, nothing would move.

Please note that SFCAs, short-chain fatty acids, are not the same as essential fatty acids (EFAs) which most of us recognize as Omega 3s in salmon and other cold-water fish. The EFAs, the essential fatty acids DHA and EPA, are dietary components which the cat herself can digest and absorb. The SFCAs are chemical by-products the gut bacteria produce which benefit the digestive system and the poop.


• Poop is not leftover food.

• The more water retained in the poop, the softer the poop. The less water, the harder the poop.

• Any treatment for constipation, including laxatives and enemas, addresses or impacts water retained in the poop and/or present in the large bowel one way or another.

What Goes Wrong?

• Transit time can play a role in constipation.

• Diet influences transit time in various ways.

• Frequency of eating may also play a role in transit time.

• Inactivity may play a role in transit time.

• Dehydration can cause constipation.

• Smooth pooping is an elegantly choreographed dance between the stool and the bowel wall.

• The stool invites the bowel to dance.

• Proper poop is like the bed in the story of The Three Bears – not too hard, not too soft.

• The stool needs to be firm enough to respond to the bowel muscle when the bowel accepts the invitation to dance, but not so firm that the stool cannot mold while passing through the anus.

• Contrary to common understanding, the stool itself is not toxic while waiting in this storage area, even if several days pass.

• If the poop is too soft to stimulate the anal glands when the cat poops, over time the glands' secretions can thicken and harden and the glands become impacted.

• It is important to note changes in the stool that do not relate to other changes, that cannot be accounted for by a change in diet or medication or routine.

• Remember to distinguish between blood on the stool as opposed to blood in the stool.

• To accept the stool's invitation to dance, the bowel's muscles and nerves need to be in good dance form, supplied with adequate levels of needed nutrients.

• A diet lacking appropriate fiber sources for the cat's gut bacteria can lead to constipation.

• Obesity can contribute to constipation.

• Various health conditions and medications can affect bowel action

and stool formation.

• Inflammation is the body's initial and innate response to whatever goes wrong, a 911 response to trouble of any kind.

• Large hairballs which manage to go down the wrong way, the long way, can result in an inflamed or impacted small intestine. Even small hairballs can be difficult to inch along.

• One reader administers a small amount of egg yolk lecithin to her cats daily to reduce the incidence of hairballs.

• The musculature of the healthy large intestine is remarkably strong.

• Straining to poop can result in vomiting.

• Any treatment for constipation, including laxatives and enemas, addresses or impacts water retention in the poop and/or the bowel one way or another.

Acute Treatment

• The first thing to do if your cat is suffering an acute bout of constipation is to contact the vet.

• The unique sensitivity of cats as a species means any treatment, whether short or long term, must be especially safe.

• If the accumulated stool in the rectum is too large to pass comfortably through the anus in response to the signal, and is rock hard, even a small enema can be very uncomfortable for the cat unless the stool is first softened.

• Too much liquid injected into the bowel may result in your cat vomiting rather than pooping. Start low and go slow!

• FLEET makes a small disposable pre-lubricated enema for human use which contains only glycerin. READ THE LABEL! Do not use any other FLEET product. FLEET also offers saline enemas which should NOT be used for cats.

• Please note! When using these little enemas, maintain steady pressure on the plunger or especially the bulb when withdrawing the device so that no suction is created. You do not want to exert suction against those tender rectal tissues.

• Only the single ingredient glycerine should be used as a suppository, in a pediatric size.

• Hairball remedies should never be forced into a struggling cat's mouth.

• Do not give a cat liquid mineral oil by mouth.

• Oral stool softeners are not a quick fix, it takes time to rehydrate the stool.

• Both Lactulose and Miralax are dose-to-effect drugs with a normal stool as the goal.

• We see different brand names, different chemical names, different appliances, but how does the bowel 'see' it?

• Learning to physically monitor the status of the constipated cat's situation helps us select the best approach and when it is time to head immediately

to the vet for assistance.


• Prevention of constipation addresses the retention of water in the

poop one way or another.

• The unique sensitivity of cats as a species means any plan, whether short or long term, must be especially safe.

• We want to prevent constipation, not chase it.

• It is not sufficient to see poop in the litter box, we want to support a healthy gut environment.

• Diet is the foundation of health, though not the only factor.

• Cats do not produce salivary amylase but they do produce pancreatic amylase.

• The question is not whether cats can digest carbohydrates, they can. The question is, what are appropriate carbohydrate sources for cats and what ratio is appropriate in their diet.

• The cat's native diet was not just protein and fat; a mouse offers about three percent carbohydrate and the mouse digestive tract contains some plant material.

• If only protein leftovers are available for gut bacteria to ferment, the more pathogenic bacteria benefit at the expense of the beneficial gut bacteria.

• Since cats have low dietary carbohydrate requirements, what to include is more critical for cats than for us omnivorous humans who can safely eat a much wider variety of plant foods in greater quantity.

• Ideally the chosen diet provides adequate and suitable fiber content but some cats may need additional help.

• Unlike dietary fiber in foods, SEB may interfere with absorption of some medications. If your cat is on medication, check with your vet or a pharmacist for guidelines about proper separation of SEB dosing and the medication.

• Changes to the diet or routine of a cat should be made gradually, to allow the cat to adjust and to permit the digestive tract to adapt.

• Functional fiber, particularly psyllium, may interfere with absorption of some medications. If your cat is on medication, check with your vet or a pharmacist for guidelines about proper separation of fiber dosing and the medication.

• Food itself is very nutritious.

• Polyethylene glycol is not propylene glycol, more familiarly called antifreeze. Polyethylene glycol is also not ethylene glycol. It is polyethylene glycol. The differences in chemical formulas matter.

• The amount of water needed to normalize the stool in response to an osmotic laxative is the same amount of water by any other method including

diet and dietary fiber.

Contact and More

The World Wide Web offers a wealth of informationn on these topics. Stick to educational, veterinary and medical sites for best results.


Here the Quick Reviews from each single page gather together on one Review page.



The First Lesson

Gut 101 – Full Version

   • Overview

   • Food

   • Mouth

   • Esophagus

   • Stomach

   Gut 101 - Condensed

Gut 102 – Full Version

   • Small Intestine

   • Large Intestine

   Gut 102 – Condensed


Gut Bacteria and Fiber


What Goes Wrong?

Acute Treatment

   • Saline Laxatives

   • Stimulant Laxatives

   • Enemas

   • Suppositories

   • Lubricant Laxatives

   • Stool Softeners

   • Osmotic Laxatives


   • Diet

   • Fiber or Prebiotics

   • Probiotics

   • Vitamins and Minerals

   • Osmotic Laxatives



Contact and More