You got the good ending

Cauterize all bleeding, remove and wash away all foreign substances, including remnants of polyps food, and non-food substances. Do your job thoroughly.
Considering the high achievement rate, it's no pressure.

You got the bad ending

Failure is a simple matter of ignoring everything and going straight to the end of each level, dealing with only the minimum of:
Retrieving the ring on Monday.
Detonating the shotgun shell on Tuesday.(see the oops! achievement)
Retrieving the pearl on Wednesday.
Washing away the remenant of a head after defeating it on Thursday.
Chasing the clown down without defeating it or washing away the parasites on Friday.

It is likely not to matter what you do on Friday after the consistent failures to do your job properly

A catastrophic lack of judgment led to a negative patient outcome

Strike the primer of the shotgun shell with the cauterizing tool on Tuesday when you encounter it. Hope you were wearing a raincoat.

Refer to fig 2. on where to aim.
Refer to fig 3. on how to miss completely.

You scanned every item in the game

Use the scanner tool to scan every different item, it is not necessary to scan the same item more than once, but when in doubt, there is no penalty for scanning the same type of item multiple times.
Here's a checklist, some items repeat, but it shouldn't hurt to scan them as soon as you encounter them.

Monday Checklist:
Healthy colon wall section.
Polyp.
Polyp remains.
Bleeding colon wound.
Fat and Calcium deposit.
Fat and Calcium deposit remnant.
Hard boiled sweet.
Sweet Corn.
Broken piece of denture.
Lost treasure(The Ring).
Ancient piece of gum.

Tuesday Checklist:
Thumb tack.
Metal shaving.
Copper coin.
Battery.
Safety pin.
Steel nail.
Barbed wire.
Razor blade.
Shotgun shell.

Wednesday Checklist:
Non-human excrement.
Unidentified aquatic blood sucking tick.
Unidentified piece of flesh.
Remnant of parasite.
Parasitic worm.
Sharp fish bone.
Egg sack.
Parasitic larva.
Aquatic bloodsucking louse.
Dead piece of louse.
Metal Fishing hook.
Undigested Fish.
Scallop shell.
Pearl

Thursday Checklist:
Human eyeball.
Human tooth.
Human ear.
Human finger.
Large inhuman tooth.
Small version of the patient's head.
Gruesome remnant of that head.

Friday Checklist:
Undigested peanut.
A door.
A fang.
What appears to be a clown.
parasite larva.

What's scarier? That there is a possibility of these medical conditions and can be explained, or that similar cases could happen and are not entirely uncommon, or impossible at all in the first place? The following are theoretical concerns and rationalizations that would be best kept to oneself. Yet here we are, ruining the horror experience.
"Boy, you must be fun at parties."

Picture credit: by Khyle

I'm sure many nurses and doctors in the medical profession will find this to be an annoying recurrence wherein a patient fails to disclose relevant information. Reasons can range from shame, or magically having slipped their mind, the same way large objects slip into their rectum. The only thing people can do in this profession despite being frustrated by this behaviour is to behave professionally.

Digestion
Client has many deposits of fat and calcium. Idiopathic colonic calcification is considered a rare phenomenon, but that's why a gastroenterologist is considered a specialist. While not uncommon or impossible to have some lingering blockages, it certainly is concerning.

Undigested material
Unknown why boiled hard candy was swallowed, and also how it left the stomach in an undigested state. It is possible that people have been sold display versions of actual candy, on the basis of scams, but it's implausible due to how low a profit margin there would be in attempting to sell such a thing.

Indigestion
Gum does not dissolve, and could pose further blockage issues in the future, regardless of how ancient it is. It would need to be removed unless it would harm the patient more to remove it, than to leave it.

Pica
Severe Inflammation, multiple ruptures, and profuse bleeding.
client is likely to set off metal detector alarms in security checkpoints, and MRIs are definitely out of the question.

Pica is a real eating disorder, and is usually linked to mental disorders, most serious cases involve trauma and stress. To show empathy for people with this disorder, it is recommended to consider their consuming of non-food items, not as a fully conscious decision, but might be a traumatic-stress response that they require may help to overcome.

"Think of your first reaction to witnessing, or the outcome of this behaviour, and now, think of how you will react the second time you encounter this same behaviour and ask yourself if you would be proud or satisfied with how you reacted to it the second time."

Consuming pointed objects
It is quite impressive for the human body to survive even a single instance this many of internal hemorrhages and traumatic injuries within the digestive system simultaneously. There have been more medical marvels and documented cases of surviving worse.

Accidentally swallowing a nail is definitely an occurrence with construction workers, who attempt to carry extra nails with their teeth to free their hands as they hammer the nail they are focusing on in to the wood.

Consuming live ammunition
Accidentally swallowing a live shotgun shell is also a plausible occurrence with someone attempting to look cool, holding a shotgun shell with their teeth as they reload a shotgun.

Consuming Razor-sharp objects
Consuming any number of razor blades however, is no coincidence even to someone afflicted with Pica, who professes a preference to consuming metallic objects.
It would be mandatory to refer this client to a psychological specialist. Regardless of the eating disorder being a stress outlet or a coping mechanism, this is life-threatening behaviour and a miracle to survive one if not three razor blades within a human or any digestive system for that matter.

Ruptures combined with the presence of metallic substances like the heavy metals of copper, lead, likely zinc, and other toxic components of a corroded AA battery should cause blood poisoning. The diet the client spoke of, likely has high doses of antibiotics and other medications preventing sepsis.
Certain medications also have a side effect of blood clotting which may explain how the client is alive, but not why they are ambulatory, and not currently in an emergency room.

Unidentified Aquatic Parasites, and general food safety
The fisherman's complaints about a feeling of a visual notion of a writhing pile of fish within his digestive system may be a psychological one, but an accurate concept with the idea of simply being in pain in multiple locations from many parasites burrowing, making multiple incursions and ruptures.

It is not entirely very uncommon to catch parasitic infections anisakiasis or bacterial infections, like vibrio vulnificus, salmonella, and listeria from consuming raw or undercooked fish.
It is popular, but incorrectly assumed that the causes are simply from Sashimi, or simply consuming dishes prepared without being fully cooked. This is correlation rather than causation as parasites and their eggs can been killed by prior freezing or heating. It is important to Carefully consider the handling and preparation of food and its source.

The extremes of assuming safety from simple freshness is a dangerous one. Freshness only reduces the chances of bacterial infection as leaving food out allows bacteria to multiply. Fortunately for this fisherman, the anisakiasis parasites have not appeared to have burrowed deeply into his other internal organs which would be a real cause for concern, however a localized immune response usually limits the lifespan and potential breeding of parasites, for most people. The fisherman however, has consistently consumed raw fish, likely to an extent that the large amount of parasites have clearly taxed his immune system beyond its capacity to get rid of the present volume of parasites.

About 18,000 new species are discovered every year, and 91% of existing organisms that live underwater have yet to be studied by science, a new species of aquatic tick and louse that can survive in the human digestive system, aquatic animals, and in seawater, would definitely be of interest to a science journal.

Audible abnomalities
as endoscopy microphones can have integrated microphones, it should not be surprising that the "Michael Jordon" of Gastroenterologists would have the latest and most high end gear, but undigested fish, making baby noises? Certain fish can make sound through alternating swim bladder compressions, and considering the acoustics of an enclosed intestinal wall, a defective microphone picking up the compression as a high pitched noise, may have a coincidental similarity of baby crying. However, the more pressing concern is that of undigested small fish, that just so happen to be in a near perfect condition lying around in a self-described "lonely" fisherman's rectum gives one pause for thought of the fish in question having made entry from the same place the endoscope has. I have nothing further to add.


Fish hooks
Considering the fishbones that are present in the fisherman's lower intestine, it is plausible that he has been inattentive and swallowed entire sections if not the fish whole. For obvious reasons, this is dangerous.

Possible Gastroparesis Caused by a foreign body, the Scallop shell?
scallops do produce pearls, although there's usually some differing colouration involved. Swallowing a scallop shell though, is more than unusual, even if there is evidence of the fisherman having swallowed fish. Theoretically, it sounds like a stupid bet with other fishermen when you have nothing to do at sea, or more embarrassingly, the scallop shell having made entry rectally for reasons. Considering the undigested condition of the small fish, the concerns about their entry points may include the scallop shell.

Additional eyeballs
Not Polycoria, but an additional eyeball in itself. However, it is unlikely that it is connected to any particular nerve endings that provide any visual responses, connected to the brain. So it is likely superfluous and non-functional organ. The condition in which it is fully formed is impressive, as are the following appendages, that will follow. What can be witnessed in this particular client, is likely the interaction between several medical conditions that are simultaneously affecting them. Having lost or won the genetic lottery several times in a row, and displaying new symptoms as the combination of both symptoms is definitely medical marvel that should be recorded on the basis of it's severity.

Hyperdontia
Usually an oral condition rather than a gastrointestinal one. However there appear to be no nerve endings of these supernumerary teeth. Despite the appearance of roots, they are easily removed with an endoscope's grabber tool, rather than specialist dentist pliers, offering little resistance to removal compared to a piece of ancient gum.

Hyperdontia is associated with many hereditary conditions, and in this case, possible genetic factors, to be very likely connected to the Polydactyly or Vanishing twin conditions that occur around birth. With the idea of these conditions existing encountering this extremely rare case becomes less fantastical, however, they must be removed, as they should be causing blockages, and the fatty calcium deposits would normally form around them. Unless they happen to actually be the calcified deposits that mimic teeth for unknown reasons. Perhaps a appearance influenced by genetic coding? That's conjecture, and highly unlikely as these calcified deposits are usually foreign bodies, that have hardened over time rather than generated from the body itself. That said, the conical teeth may look like fangs, but may just simply be likely that they are teeth from an unmistakably British client.


There are 2 possible explanations and general medical conditions associated with the patient's condition
Polycephaly, and Polydactyly, as subcategories of Vanishing Twin Syndrome
A malformed growth that resembles the client's head has been observed, which may be vanishing twin Syndrome. This would explain the combination of symptoms that would be associated with vanishing twin Syndrome, such as Polycephaly or even the Polydactyly, which are both in the category of birth defects.

"A vanishing twin Syndrome also known as twin resorption, is a fetus in a multigestation pregnancy that dies in utero and is then partially or completely reabsorbed. In some instances, the dead twin is compressed into a flattened, parchment-like state known as fetus papyraceus"
Vanishing twins occur in up to one of every eight multifetus pregnancies and may not even be known in most cases.

Polycephaly, is usually the medical condition of having multiple heads, being functional or non-functional is not a requisite to fall under this category of diagnosis.

Polydactyly, is usually the medical condition of having additional fingers, present at birth, and often hereditary.

There are high profile cases of these, usually seen externally rather than internally, and never recorded to be observed simultaneously in most medical records of abnomalities. It is also difficult to find medical literature of these cases of this occurring in the lower intestinal tract.

Teratoma
This disorder, is classified as a tumor that has growths of certain unusual features, such as teeth, hair, bone and muscle tissue.

Why this is significant, is because symptoms of Teratoma have been observed manifesting internally, in and around organs of the afflicted, where most cases of Polycephaly, and Polydactyly, have been usually is observed externally.

Fictional counterparts, and combinations of these conditions
Maske Tumor or Masketoma is fictional and an aggressive form of teratoma, but in the case of the client, manifesting in the digestive tract, instead of externally on the body. This condition is found in the realm of science fiction.
Popular in phenomenon in Japanese body horror, termed human-face wounds or "jinmen-sou" or "Jinmenso." This condition is found in the realm of folklore.

They both share similar characteristics that, to quote a translation from another fictional and dubious medical practitioner:
"it's extremely rare, malignant tumors take cues from your genes and recreate images of your body in themselves."

These concepts have made an appearance in the same origins of their folklore -Japan: Junji Itos works, Franken Fran, and Battle Angel Alita Mars Chronicle.


Personal notes:
If fingerprints can be taken, from the additional digits, will they be similar to the client's primary fingerprints?

The client stood up like a new man with a big smile on his face and left looking like a new man, unable to sit.

Mind and body are very much connected
Though rare, there are cases of mental health, manifesting themselves as physical ailments, through more mundane and less symbolic means with the patient's connection to the circus. The previous day's case was the body affected by the mind, as the client believed the body was demanding food, which is exactly what the body usually does in less grandiose fashion by usually grumbling and growling. The point though, is that there's enough context to suggest an extreme case of the body perhaps being affected by the mind, or even more interesting, a foreign parasite's fight/flight response being affected by the mind and body, a causing physical evolutionary adaptation.
An adaptation to ward off what exactly? a repressed Coulrophobia is possible, which may explain what follows.
Or simply that the mention of the circus towards our Michael Jordan of gastroenterologists has his own personal repressed traumas related to the circus, manifesting in some hallucinatory way. Fortunately, retirement is around the corner, and the resultant free time can be used to see a therapist.

Stealing peanuts from the elephants
Peanuts are very easily susceptible to parasites and mold, being one of the crops most sprayed with pesticides. Commercially sold peanuts are usually more hygienic, but when purchased from a wholesaler as animal feeds, it's unlikely to be as clean or stored well.

Whole peanuts were found in the colon despite the client insisting that food was chewed sufficiently. This indicates either the client is not forthcoming with personal information or that they have been careless with food consumption. The undigested condition of the peanuts makes me doubtful of the contents of his colon having made entry orally.
The statement of mainly consuming soup in the past week may be true, but at the same time, client stated that their diet has been unchanged, therefore unless their usual diet has always been soup and peanuts, their statement contradicts the idea that Soup may unusual to their regular diet. It may be necessary to ask clarification as the patient may simply be very unconcerned with what they eat and are unable to provide accurate information.
Future visitation would require the patient to elaborate on what is considered a perfectly normal bowel movement.

"Life has many doors, Edd boy."
Considering the size of the semi-functional door within the colon, someone has either consumed through either orifice part of some poor child's doll house and saw fit not to disclose this information. The inside of the door itself being of a flat texture, makes it likely that it is a cheap product that likely to be a child's toy. Considering the way it is lodged, surgery may be required to remove it as blockages are a certainty with it remaining in the patient's colon.

Addressing the clown in the colon
Lets discuss the observations:
A large parasitic creature has taken residence in the patient's colon.
It resembles a clown.
Considering the parasite larva it leaves around, it is definitely a foreign body.
It is likely to be made entirely out of parasites as it leaves behind no bones.
The teeth that are embedded in the colon, and in the "clown" have no roots, so no human dental structure of functionality is likely. With the point being that it is a foreign body, it's not Hyperdontia.
Loss of eyes do not hinder movement or navigation for this clown, so these eyes may not even be functional and may just be for show.

There are animals out in the wild that exhibit the same behaviours and can take on the same appearances as this clown parasite. For example, Butterflies' wing patterns and Eyespot markings that are believed to ward off predators. This trait need not be exclusive to the butterfly, should this parasite have this particular trait, it could mimic a face easily. The same way ants and bees may work together fulfill tasks from attacking an intruder to using each other to float, it is possible that an undiscovered collection of parasites may attempt a formation to hinder or scare possible predators.

Pareidolia
Perhaps all of what has been seen is simply within our heads, or even maybe partially what has been seen is just that. Perhaps there's a latent Coulrophobia, that exists, causing one in context, to hear circus music as a wandering thought. Certainly, seeing faces where there isn't one, is a human response, as much as an animal taking advantage of that phenomenon.

It would be certainly outside what most people could psychologically handle should it actually exist despite being actually quite mundane.

Coulrophobia
The phobia is not simply a fear that occurs when encountering a clown, but can also manifest through Pareidolia to find any similarities to a clown and then perceive it into existence. It may sound like a reach, but numerous cases of people with this real fear do struggle with a heightened reflex that would have as a matter of human psychology, subconsciously search for any visual resemblance of their fears.
While Steven King's "It" has popularized this fear, it bears its roots in a real life serial killer- John Wayne Gacy, Jr. who appeared as "Pogo the clown."