Influence of body position and stool characteristics on defecation in humans.

“Whether defecation is influenced by body position or stool characteristics is unclear. We investigated effects of body position, presence of stool-like sensation, and stool form on defecation patterns and manometric profiles. Rectal and anal pressures were assessed in 25 healthy volunteers during attempted defecation either in the lying or sitting positions and with balloon-filled or empty rectum. (more…)

“OBJECTIVE: Traditionally, barium paste has been used for performing defecography. Because this substance is not stool-like, barium defecography may not accurately represent defecatory function. Our aim was to prospectively compare the utility of a new artificial stool, “FECOM”–a silicon-filled and barium-coated, deformable device the shape and consistency of which mimicked a normal formed stool with that of barium paste. METHODS: Defecography was performed after placing FECOM or barium paste in a random order in 12 healthy subjects (two men and 10 women). We evaluated the changes in anorectal angle, rectal morphology, rectal sensation, and the subjects’ preference for a “stool-like” device. (more…)

Innate olfactory preferences in dung beetles.

“The effects of insect larval diet on adult olfactory responses to host-plant or food volatiles are still debated. The induction of adult host preferences has been studied in insects with diverse ecologies, including parasitoids, flower-visitors and phytophagous species. We investigated this question for the first time in a coprophagous insect species. Larvae of the French scarab dung beetle Agrilinus constans were reared on four different artificial substrates containing dung from cattle, horse, sheep or wild boar, and responses of imagos to dung volatiles were then behaviourally tested in an olfactometer. (more…)

Chemical processes in the deep interior of Uranus.

“The unusual magnetic fields of the planets Uranus and Neptune represent important observables for constraining and developing deep interior models. Models suggests that the unusual non-dipolar and non-axial magnetic fields of these planets originate from a thin convective and conducting shell of material around a stably stratified fluid core. Here, we present an experimental and computational study of the physical properties of a fluid representative of the interior of Uranus and Neptune. (more…)

It’s insect week on NCBI ROFL!  All week long we’ll be featuring the funniest scientific papers about our favorite creepy crawlies.  Enjoy!

“A 52-year-old woman with a history of depression was referred by her primary physician for colorectal cancer screening. She had no family history of colorectal cancer and a review of systems was positive for abdominal bloating. Bowel preparation was done using 4 L of polyethylene glycol the evening prior to screening colonoscopy. The procedure was uncomplicated with no gross mucosal pathology, however, an insect was found in the transverse colon (Fig. 1, to the left), was found in the transverse colon on a routine screening colonoscopy.). (more…)

It’s case study flashback week on NCBI ROFL! All this week we’ll be featuring some of our favorite medical case studies from the archives. Enjoy!

“We present the case of a 63-year-old man who had inserted a salami into his anal canal for sexual stimulation–the commonest reason for inserting foreign bodies–and who subsequently required a laparotomy for its removal. (more…)

Field studies on inhibitory influence of skin pressure exerted by a body compensatory brassiere on the amount of feces.

“The present experiment investigated the effects of skin pressure produced by a body compensatory brassiere [a brassiere with underwires] on defecation activity. Seven healthy females (11-41 yrs) volunteered as participants, being free of medication and constipation. The experiment lasted 3 weeks. The participants did not wear the body compensatory brassiere for the first week, wore it during waking hours for the second week, and again did not wear it for the third week. Whenever they desired to defecate, they did so and then weighted the amount of feces immediately by themselves. (more…)

“Falsification of illness occurs when a patient fabricates symptoms or induces a physical illness. A recent review of the literature covering the past 3 decades identified 42 published case studies of falsified illness in children younger than 18 years of age (1). The psychiatric term for illness falsification is “factitious disorder,” which is defined as an intentional, self-inflicted, or fabricated illness or symptom motivated solely by the individual’s need to assume the sick role, without external incentives (2). Children are at risk of developing a chronic pattern of illness falsification with the potential for serious self-harm as the sophistication of their fabrications increase. Therefore, early detection and intervention is essential (1). We report a unique case of a factitious illness in which an adolescent diluted stool samples with water to feign chronic diarrhea. (more…)

Gas production by feces of infants.

“BACKGROUND: Intestinal gas is thought to be the cause abdominal discomfort in infants. Little is known about the type and amount of gas produced by the infant’s colonic microflora and whether diet influences gas formation. METHODS: Fresh stool specimens were collected from 10 breast-fed infants, 5 infants fed a soy-based formula, and 3 infants fed a milk-based formula at approximately 1, 2, and 3 months of age. Feces were incubated anaerobically for 4 hours at 37 degrees C followed by quantitation of hydrogen (H2), methane (CH4), carbon dioxide (CO2), hydrogen sulfide (H2S), methanethiol (CH3SH), and dimethyl sulfide (CH3SCH3) in the head-space. (more…)

Investigation of normal flatus production in healthy volunteers.

“Flatulence can cause discomfort and distress but there are few published data of normal patterns and volumes. Twenty four hour collections were made using a rectal catheter in 10 normal volunteers taking their normal diet plus 200 g baked beans. (more…)