図３〜図５は省略．全図で描出されている無数の石灰化像は小児期に罹患した腸結核・結核性腹膜炎による腸間膜と後腹膜リンパ節の石灰化であろう．肝周囲と骨盤腔内には腹水を認めないが，図１３で右結腸傍溝に少量存在する（※）．拡張した小腸の壁は良好な造影効果を示し，腸間膜に浮腫や液貯留を示唆する濃度上昇を認めない（図１３の▲は図１４の小腸１７と１９のpartial volume effectと呼ばれる現象で腸間膜の濃度上昇ではない）．少量の腹水と拡張した小腸がgaslessであること以外に絞扼性小腸閉塞の所見はなく，単純閉塞の可能性が高い．図２０から追跡すると，Aは図１６で閉塞するが1は図７の32となり頭側へ伸展し，図１６近辺で閉塞しないので単純閉塞の確定診断となる．図１５と図１６で虚脱した小腸（SB）が閉塞部位に隣接しており図１６の↑が移行部（transition zone）である．腫瘍性病変，腸重積や外部から圧排する病変などを認めないので閉塞の原因は癒着によるものと解釈する．図２０のA〜図１６のEは“小腸内糞便”(small bowel feces)　と呼ばれる所見で，単純閉塞腸管に見られ閉塞部位を示す場合が多い（下記文献参照）．経鼻胃管を挿入し保存的に治癒した．

partial volume effect（部分容積効果）：あるＣＴ値を持った物体がスライスの一部にしか含まれないとすると，その周囲の構造のＣＴ値と平均化され，物体は真のＣＴ値よりも高いあるいは低いＣＴ値を持つ構造として表現され，辺縁がぼやける．これをpartial volume effectと言い，上図の右2つにpartial volume effectが発生する．

文献考察：小腸内糞便（small bowel feces ）．小腸閉塞例の55.9％に認められ，閉塞部位または閉塞部位近辺を意味する場合が多い．
AJR Am J Roentgenol. 2004 Nov;183(5):1361-6.
Frequency and relevance of the "small-bowel feces" sign on CT in patients with small-bowel obstruction.
Lazarus DE, Slywotsky C, Bennett GL, Megibow AJ, Macari M.

OBJECTIVE: We sought to determine the incidence of the "small-bowel feces" sign (SBFS) in patients with small-bowel obstruction (SBO) and whether it can be used to accurately locate the point of obstruction. SUBJECTS AND METHODS: From November 2002 until March 2003, 34 consecutive adult patients with CT findings of small-bowel obstruction were prospectively evaluated. The CT findings used to diagnose small-bowel obstruction were a dilated proximal small bowel and a collapsed distal small bowel and colon. CT scans were evaluated to determine the degree of obstruction (mild, moderate, or high-grade), the presence or absence of the SBFS (defined as particulate-type material in the dilated small bowel), the location of the SBFS in relation to the transition zone, and the cause of the obstruction. Mild obstruction was defined as a slight discrepancy between the caliber of the proximal and that of the distal small bowel; moderate SBO was defined as a discrepancy of 50% or more between the calibers of the proximal and the distal small bowel; and high-grade SBO was considered to be present if the distal small bowel and the colon had collapsed. The cause of the obstruction was determined from surgical findings or a combination of CT findings, follow-up barium studies, and clinical assessment. RESULTS: The SBFS was present in 19 (55.9%) of 34 patients with SBO. The degree of SBO was mild in six, moderate in 11, and high-grade in 17 of the patients. The SBFS was present in one of the six patients (16.6%) with mild, eight (72.7%) of the 11 with moderate, and 10 (58.8%) of the 17 with high-grade SBO. In all patients in whom the SBFS was present, the particulate material could be traced to the point of transition and was most conspicuous in the transition zone. The length of fecallike material ranged from 2 to 25 cm and was longer in moderate and high-grade SBO than in mild SBO. The cause of the SBO was an adhesion in 20 patients, a hernia in four patients, Crohn's disease in four patients, a tumor in three patients, and other miscellaneous causes in three patients. CONCLUSION: When present on CT, the SBFS can be used to help locate the transition zone in patients with SBO. The sign is present more frequently in patients with moderate and high degrees of SBO.PMID: 15505304